Functions for Working with Dates and Times
Most functions in this section accept an optional time zone argument, e.g. Europe/Amsterdam
. In this case, the time zone is the specified one instead of the local (default) one.
Example
SELECT
toDateTime('2016-06-15 23:00:00') AS time,
toDate(time) AS date_local,
toDate(time, 'Asia/Yekaterinburg') AS date_yekat,
toString(time, 'US/Samoa') AS time_samoa
┌────────────────time─┬─date_local─┬─date_yekat─┬─time_samoa──────────┐
│ 2016-06-15 23:00:00 │ 2016-06-15 │ 2016-06-16 │ 2016-06-15 09:00:00 │
└─────────────────────┴────────────┴────────────┴─────────────────────┘
makeDate
Creates a Date
- from a year, month and day argument, or
- from a year and day of year argument.
Syntax
makeDate(year, month, day);
makeDate(year, day_of_year);
Alias:
MAKEDATE(year, month, day);
MAKEDATE(year, day_of_year);
Arguments
year
— Year. Integer, Float or Decimal.month
— Month. Integer, Float or Decimal.day
— Day. Integer, Float or Decimal.day_of_year
— Day of the year. Integer, Float or Decimal.
Returned value
- A date created from the arguments.
Type: Date.
Example
Create a Date from a year, month and day:
SELECT makeDate(2023, 2, 28) AS Date;
Result:
┌───────date─┐
│ 2023-02-28 │
└────────────┘
Create a Date from a year and day of year argument:
SELECT makeDate(2023, 42) AS Date;
Result:
┌───────date─┐
│ 2023-02-11 │
└────────────┘
makeDate32
Like makeDate but produces a Date32.
makeDateTime
Creates a DateTime from a year, month, day, hour, minute and second argument.
Syntax
makeDateTime(year, month, day, hour, minute, second[, timezone])
Arguments
year
— Year. Integer, Float or Decimal.month
— Month. Integer, Float or Decimal.day
— Day. Integer, Float or Decimal.hour
— Hour. Integer, Float or Decimal.minute
— Minute. Integer, Float or Decimal.second
— Second. Integer, Float or Decimal.timezone
— Timezone for the returned value (optional).
Returned value
- A date with time created from the arguments.
Type: DateTime.
Example
SELECT makeDateTime(2023, 2, 28, 17, 12, 33) AS DateTime;
Result:
┌────────────DateTime─┐
│ 2023-02-28 17:12:33 │
└─────────────────────┘
makeDateTime64
Like makeDateTime but produces a DateTime64.
Syntax
makeDateTime64(year, month, day, hour, minute, second[, fraction[, precision[, timezone]]])
timestamp
Converts the first argument 'expr' to type DateTime64(6). If a second argument 'expr_time' is provided, it adds the specified time to the converted value.
Syntax
timestamp(expr[, expr_time])
Alias: TIMESTAMP
Arguments
Examples
SELECT timestamp('2023-12-31') as ts;
Result:
┌─────────────────────────ts─┐
│ 2023-12-31 00:00:00.000000 │
└────────────────────────────┘
SELECT timestamp('2023-12-31 12:00:00', '12:00:00.11') as ts;
Result:
┌─────────────────────────ts─┐
│ 2024-01-01 00:00:00.110000 │
└────────────────────────────┘
Returned value
- DateTime64(6)
timeZone
Returns the timezone of the current session, i.e. the value of setting session_timezone. If the function is executed in the context of a distributed table, then it generates a normal column with values relevant to each shard, otherwise it produces a constant value.
Syntax
timeZone()
Alias: timezone
.
Returned value
- Timezone.
Type: String.
Example
SELECT timezone()
Result:
┌─timezone()─────┐
│ America/Denver │
└────────────────┘
See also
serverTimeZone
Returns the timezone of the server, i.e. the value of setting timezone. If the function is executed in the context of a distributed table, then it generates a normal column with values relevant to each shard. Otherwise, it produces a constant value.
Syntax
serverTimeZone()
Alias: serverTimezone
.
Returned value
- Timezone.
Type: String.
Example
SELECT serverTimeZone()
Result:
┌─serverTimeZone()─┐
│ UTC │
└──────────────────┘
See also
toTimeZone
Converts a date or date with time to the specified time zone. Does not change the internal value (number of unix seconds) of the data, only the value's time zone attribute and the value's string representation changes.
Syntax
toTimezone(value, timezone)
Alias: toTimezone
.
Arguments
value
— Time or date and time. DateTime64.timezone
— Timezone for the returned value. String. This argument is a constant, becausetoTimezone
changes the timezone of a column (timezone is an attribute ofDateTime*
types).
Returned value
- Date and time.
Type: DateTime.
Example
SELECT toDateTime('2019-01-01 00:00:00', 'UTC') AS time_utc,
toTypeName(time_utc) AS type_utc,
toInt32(time_utc) AS int32utc,
toTimeZone(time_utc, 'Asia/Yekaterinburg') AS time_yekat,
toTypeName(time_yekat) AS type_yekat,
toInt32(time_yekat) AS int32yekat,
toTimeZone(time_utc, 'US/Samoa') AS time_samoa,
toTypeName(time_samoa) AS type_samoa,
toInt32(time_samoa) AS int32samoa
FORMAT Vertical;
Result:
Row 1:
──────
time_utc: 2019-01-01 00:00:00
type_utc: DateTime('UTC')
int32utc: 1546300800
time_yekat: 2019-01-01 05:00:00
type_yekat: DateTime('Asia/Yekaterinburg')
int32yekat: 1546300800
time_samoa: 2018-12-31 13:00:00
type_samoa: DateTime('US/Samoa')
int32samoa: 1546300800
See Also
- formatDateTime - supports non-constant timezone.
- toString - supports non-constant timezone.
timeZoneOf
Returns the timezone name of DateTime or DateTime64 data types.
Syntax
timeZoneOf(value)
Alias: timezoneOf
.
Arguments
value
— Date and time. DateTime or DateTime64.
Returned value
- Timezone name.
Type: String.
Example
SELECT timezoneOf(now());
Result:
┌─timezoneOf(now())─┐
│ Etc/UTC │
└───────────────────┘
timeZoneOffset
Returns the timezone offset in seconds from UTC. The function daylight saving time and historical timezone changes at the specified date and time into account. The IANA timezone database is used to calculate the offset.
Syntax
timeZoneOffset(value)
Alias: timezoneOffset
.
Arguments
value
— Date and time. DateTime or DateTime64.
Returned value
- Offset from UTC in seconds.
Type: Int32.
Example
SELECT toDateTime('2021-04-21 10:20:30', 'America/New_York') AS Time, toTypeName(Time) AS Type,
timeZoneOffset(Time) AS Offset_in_seconds, (Offset_in_seconds / 3600) AS Offset_in_hours;
Result:
┌────────────────Time─┬─Type─────────────────────────┬─Offset_in_seconds─┬─Offset_in_hours─┐
│ 2021-04-21 10:20:30 │ DateTime('America/New_York') │ -14400 │ -4 │
└─────────────────────┴──────────────────────────────┴───────────────────┴─────────────────┘
toYear
Returns the year component (AD) of a date or date with time.
Syntax
toYear(value)
Alias: YEAR
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The year of the given date/time
Type: UInt16
Example
SELECT toYear(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toYear(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023 │
└───────────────────────────────────────────┘
toQuarter
Returns the quarter (1-4) of a date or date with time.
Syntax
toQuarter(value)
Alias: QUARTER
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The quarter of the year (1, 2, 3 or 4) of the given date/time
Type: UInt8
Example
SELECT toQuarter(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toQuarter(toDateTime('2023-04-21 10:20:30'))─┐
│ 2 │
└──────────────────────────────────────────────┘
toMonth
Returns the month component (1-12) of a date or date with time.
Syntax
toMonth(value)
Alias: MONTH
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The month of the year (1 - 12) of the given date/time
Type: UInt8
Example
SELECT toMonth(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toMonth(toDateTime('2023-04-21 10:20:30'))─┐
│ 4 │
└────────────────────────────────────────────┘
toDayOfYear
Returns the number of the day within the year (1-366) of a date or date with time.
Syntax
toDayOfYear(value)
Alias: DAYOFYEAR
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The day of the year (1 - 366) of the given date/time
Type: UInt16
Example
SELECT toDayOfYear(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toDayOfYear(toDateTime('2023-04-21 10:20:30'))─┐
│ 111 │
└────────────────────────────────────────────────┘
toDayOfMonth
Returns the number of the day within the month (1-31) of a date or date with time.
Syntax
toDayOfMonth(value)
Aliases: DAYOFMONTH
, DAY
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The day of the month (1 - 31) of the given date/time
Type: UInt8
Example
SELECT toDayOfMonth(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toDayOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│ 21 │
└─────────────────────────────────────────────────┘
toDayOfWeek
Returns the number of the day within the week of a date or date with time.
The two-argument form of toDayOfWeek()
enables you to specify whether the week starts on Monday or Sunday, and whether the return value should be in the range from 0 to 6 or 1 to 7. If the mode argument is omitted, the default mode is 0. The time zone of the date can be specified as the third argument.
Mode | First day of week | Range |
---|---|---|
0 | Monday | 1-7: Monday = 1, Tuesday = 2, ..., Sunday = 7 |
1 | Monday | 0-6: Monday = 0, Tuesday = 1, ..., Sunday = 6 |
2 | Sunday | 0-6: Sunday = 0, Monday = 1, ..., Saturday = 6 |
3 | Sunday | 1-7: Sunday = 1, Monday = 2, ..., Saturday = 7 |
Syntax
toDayOfWeek(t[, mode[, timezone]])
Alias: DAYOFWEEK
.
Arguments
t
- a Date, Date32, DateTime or DateTime64mode
- determines what the first day of the week is. Possible values are 0, 1, 2 or 3. See the table above for the differences.timezone
- optional parameter, it behaves like any other conversion function
The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.
Returned value
- The day of the week (1-7), depending on the chosen mode, of the given date/time
Example
The following date is April 21, 2023, which was a Friday:
SELECT
toDayOfWeek(toDateTime('2023-04-21')),
toDayOfWeek(toDateTime('2023-04-21'), 1)
Result:
┌─toDayOfWeek(toDateTime('2023-04-21'))─┬─toDayOfWeek(toDateTime('2023-04-21'), 1)─┐
│ 5 │ 4 │
└───────────────────────────────────────┴──────────────────────────────────────────┘
toHour
Returns the hour component (0-24) of a date with time.
Assumes that if clocks are moved ahead, it is by one hour and occurs at 2 a.m., and if clocks are moved back, it is by one hour and occurs at 3 a.m. (which is not always exactly when it occurs - it depends on the timezone).
Syntax
toHour(value)
Alias: HOUR
Arguments
value
- a DateTime or DateTime64
Returned value
- The hour of the day (0 - 23) of the given date/time
Type: UInt8
Example
SELECT toHour(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toHour(toDateTime('2023-04-21 10:20:30'))─┐
│ 10 │
└───────────────────────────────────────────┘
toMinute
Returns the minute component (0-59) a date with time.
Syntax
toMinute(value)
Alias: MINUTE
Arguments
value
- a DateTime or DateTime64
Returned value
- The minute of the hour (0 - 59) of the given date/time
Type: UInt8
Example
SELECT toMinute(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toMinute(toDateTime('2023-04-21 10:20:30'))─┐
│ 20 │
└─────────────────────────────────────────────┘
toSecond
Returns the second component (0-59) of a date with time. Leap seconds are not considered.
Syntax
toSecond(value)
Alias: SECOND
Arguments
value
- a DateTime or DateTime64
Returned value
- The second in the minute (0 - 59) of the given date/time
Type: UInt8
Example
SELECT toSecond(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toSecond(toDateTime('2023-04-21 10:20:30'))─┐
│ 30 │
└─────────────────────────────────────────────┘
toMillisecond
Returns the millisecond component (0-999) of a date with time.
Syntax
toMillisecond(value)
*Arguments**
value
- DateTime or DateTime64
Alias: MILLISECOND
SELECT toMillisecond(toDateTime64('2023-04-21 10:20:30.456', 3))
Result:
┌──toMillisecond(toDateTime64('2023-04-21 10:20:30.456', 3))─┐
│ 456 │
└────────────────────────────────────────────────────────────┘
Returned value
- The millisecond in the minute (0 - 59) of the given date/time
Type: UInt16
toUnixTimestamp
Converts a string, a date or a date with time to the Unix Timestamp in UInt32
representation.
If the function is called with a string, it accepts an optional timezone argument.
Syntax
toUnixTimestamp(date)
toUnixTimestamp(str, [timezone])
Returned value
- Returns the unix timestamp.
Type: UInt32
.
Example
SELECT
'2017-11-05 08:07:47' AS dt_str,
toUnixTimestamp(dt_str) AS from_str,
toUnixTimestamp(dt_str, 'Asia/Tokyo') AS from_str_tokyo,
toUnixTimestamp(toDateTime(dt_str)) AS from_datetime,
toUnixTimestamp(toDateTime64(dt_str, 0)) AS from_datetime64,
toUnixTimestamp(toDate(dt_str)) AS from_date,
toUnixTimestamp(toDate32(dt_str)) AS from_date32
FORMAT Vertical;
Result:
Row 1:
──────
dt_str: 2017-11-05 08:07:47
from_str: 1509869267
from_str_tokyo: 1509836867
from_datetime: 1509869267
from_datetime64: 1509869267
from_date: 1509840000
from_date32: 1509840000
The return type of toStartOf*
, toLastDayOf*
, toMonday
, timeSlot
functions described below is determined by the configuration parameter enable_extended_results_for_datetime_functions which is 0
by default.
Behavior for
enable_extended_results_for_datetime_functions = 0
:- Functions
toStartOfYear
,toStartOfISOYear
,toStartOfQuarter
,toStartOfMonth
,toStartOfWeek
,toLastDayOfWeek
,toLastDayOfMonth
,toMonday
returnDate
orDateTime
. - Functions
toStartOfDay
,toStartOfHour
,toStartOfFifteenMinutes
,toStartOfTenMinutes
,toStartOfFiveMinutes
,toStartOfMinute
,timeSlot
returnDateTime
. Though these functions can take values of the extended typesDate32
andDateTime64
as an argument, passing them a time outside the normal range (year 1970 to 2149 forDate
/ 2106 forDateTime
) will produce wrong results.
- Functions
enable_extended_results_for_datetime_functions = 1
:- Functions
toStartOfYear
,toStartOfISOYear
,toStartOfQuarter
,toStartOfMonth
,toStartOfWeek
,toLastDayOfWeek
,toLastDayOfMonth
,toMonday
returnDate
orDateTime
if their argument is aDate
orDateTime
, and they returnDate32
orDateTime64
if their argument is aDate32
orDateTime64
. - Functions
toStartOfDay
,toStartOfHour
,toStartOfFifteenMinutes
,toStartOfTenMinutes
,toStartOfFiveMinutes
,toStartOfMinute
,timeSlot
returnDateTime
if their argument is aDate
orDateTime
, and they returnDateTime64
if their argument is aDate32
orDateTime64
.
- Functions
toStartOfYear
Rounds down a date or date with time to the first day of the year. Returns the date as a Date
object.
Syntax
toStartOfYear(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The first day of the year of the input date/time
Type: Date
Example
SELECT toStartOfYear(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toStartOfYear(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-01-01 │
└──────────────────────────────────────────────────┘
toStartOfISOYear
Rounds down a date or date with time to the first day of the ISO year, which can be different than a "regular" year. (See https://en.wikipedia.org/wiki/ISO_week_date.)
Syntax
toStartOfISOYear(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The first day of the year of the input date/time
Type: Date
Example
SELECT toStartOfISOYear(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toStartOfISOYear(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-01-02 │
└─────────────────────────────────────────────────────┘
toStartOfQuarter
Rounds down a date or date with time to the first day of the quarter. The first day of the quarter is either 1 January, 1 April, 1 July, or 1 October. Returns the date.
Syntax
toStartOfQuarter(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The first day of the quarter of the given date/time
Type: Date
Example
SELECT toStartOfQuarter(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toStartOfQuarter(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-04-01 │
└─────────────────────────────────────────────────────┘
toStartOfMonth
Rounds down a date or date with time to the first day of the month. Returns the date.
Syntax
toStartOfMonth(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The first day of the month of the given date/time
Type: Date
Example
SELECT toStartOfMonth(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toStartOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-04-01 │
└───────────────────────────────────────────────────┘
The behavior of parsing incorrect dates is implementation specific. ClickHouse may return zero date, throw an exception, or do “natural” overflow.
toLastDayOfMonth
Rounds a date or date with time to the last day of the month. Returns the date.
Syntax
toLastDayOfMonth(value)
Alias: LAST_DAY
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The last day of the month of the given date/time
Type: Date
Example
SELECT toLastDayOfMonth(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toLastDayOfMonth(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-04-30 │
└─────────────────────────────────────────────────────┘
toMonday
Rounds down a date or date with time to the nearest Monday. Returns the date.
Syntax
toMonday(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The date of the nearest Monday on or prior to the given date
Type: Date
Example
SELECT
toMonday(toDateTime('2023-04-21 10:20:30')), /* a Friday */
toMonday(toDate('2023-04-24')), /* already a Monday */
Result:
┌─toMonday(toDateTime('2023-04-21 10:20:30'))─┬─toMonday(toDate('2023-04-24'))─┐
│ 2023-04-17 │ 2023-04-24 │
└─────────────────────────────────────────────┴────────────────────────────────┘
toStartOfWeek
Rounds a date or date with time down to the nearest Sunday or Monday. Returns the date. The mode argument works exactly like the mode argument in function toWeek()
. If no mode is specified, it defaults to 0.
Syntax
toStartOfWeek(t[, mode[, timezone]])
Arguments
t
- a Date, Date32, DateTime or DateTime64mode
- determines the first day of the week as described in the toWeek() functiontimezone
- Optional parameter, it behaves like any other conversion function
Returned value
- The date of the nearest Sunday or Monday on or prior to the given date, depending on the mode
Type: Date
Example
SELECT
toStartOfWeek(toDateTime('2023-04-21 10:20:30')), /* a Friday */
toStartOfWeek(toDateTime('2023-04-21 10:20:30'), 1), /* a Friday */
toStartOfWeek(toDate('2023-04-24')), /* a Monday */
toStartOfWeek(toDate('2023-04-24'), 1) /* a Monday */
FORMAT Vertical
Result:
Row 1:
──────
toStartOfWeek(toDateTime('2023-04-21 10:20:30')): 2023-04-16
toStartOfWeek(toDateTime('2023-04-21 10:20:30'), 1): 2023-04-17
toStartOfWeek(toDate('2023-04-24')): 2023-04-23
toStartOfWeek(toDate('2023-04-24'), 1): 2023-04-24
toLastDayOfWeek
Rounds a date or date with time up to the nearest Saturday or Sunday. Returns the date.
The mode argument works exactly like the mode argument in function toWeek()
. If no mode is specified, mode is assumed as 0.
Syntax
toLastDayOfWeek(t[, mode[, timezone]])
Arguments
t
- a Date, Date32, DateTime or DateTime64mode
- determines the last day of the week as described in the toWeek() functiontimezone
- Optional parameter, it behaves like any other conversion function
Returned value
- The date of the nearest Sunday or Monday on or after the given date, depending on the mode
Type: Date
Example
SELECT
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30')), /* a Friday */
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30'), 1), /* a Friday */
toLastDayOfWeek(toDate('2023-04-22')), /* a Saturday */
toLastDayOfWeek(toDate('2023-04-22'), 1) /* a Saturday */
FORMAT Vertical
Result:
Row 1:
──────
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30')): 2023-04-22
toLastDayOfWeek(toDateTime('2023-04-21 10:20:30'), 1): 2023-04-23
toLastDayOfWeek(toDate('2023-04-22')): 2023-04-22
toLastDayOfWeek(toDate('2023-04-22'), 1): 2023-04-23
toStartOfDay
Rounds down a date with time to the start of the day.
Syntax
toStartOfDay(value)
Arguments
value
- a Date, Date32, DateTime or DateTime64
Returned value
- The start of the day of the given date/time
Type: DateTime
Example
SELECT toStartOfDay(toDateTime('2023-04-21 10:20:30'))
Result:
┌─toStartOfDay(toDateTime('2023-04-21 10:20:30'))─┐
│ 2023-04-21 00:00:00 │
└─────────────────────────────────────────────────┘
toStartOfHour
Rounds down a date with time to the start of the hour.
Syntax
toStartOfHour(value)
Arguments
value
- a DateTime or DateTime64
Returned value
- The start of the hour of the given date/time
Type: DateTime
Example
SELECT
toStartOfHour(toDateTime('2023-04-21 10:20:30')),
toStartOfHour(toDateTime64('2023-04-21', 6))
Result:
┌─toStartOfHour(toDateTime('2023-04-21 10:20:30'))─┬─toStartOfHour(toDateTime64('2023-04-21', 6))─┐
│ 2023-04-21 10:00:00 │ 2023-04-21 00:00:00 │
└──────────────────────────────────────────────────┴──────────────────────────────────────────────┘
toStartOfMinute
Rounds down a date with time to the start of the minute.
Syntax
toStartOfMinute(value)
Arguments
value
- a DateTime or DateTime64
Returned value
- The start of the minute of the given date/time
Type: DateTime
Example
SELECT
toStartOfMinute(toDateTime('2023-04-21 10:20:30')),
toStartOfMinute(toDateTime64('2023-04-21 10:20:30.5300', 8))
FORMAT Vertical
Result:
Row 1:
──────
toStartOfMinute(toDateTime('2023-04-21 10:20:30')): 2023-04-21 10:20:00
toStartOfMinute(toDateTime64('2023-04-21 10:20:30.5300', 8)): 2023-04-21 10:20:00
toStartOfSecond
Truncates sub-seconds.
Syntax
toStartOfSecond(value, [timezone])
Arguments
value
— Date and time. DateTime64.timezone
— Timezone for the returned value (optional). If not specified, the function uses the timezone of thevalue
parameter. String.
Returned value
- Input value without sub-seconds.
Type: DateTime64.
Examples
Query without timezone:
WITH toDateTime64('2020-01-01 10:20:30.999', 3) AS dt64
SELECT toStartOfSecond(dt64);
Result:
┌───toStartOfSecond(dt64)─┐
│ 2020-01-01 10:20:30.000 │
└─────────────────────────┘
Query with timezone:
WITH toDateTime64('2020-01-01 10:20:30.999', 3) AS dt64
SELECT toStartOfSecond(dt64, 'Asia/Istanbul');
Result:
┌─toStartOfSecond(dt64, 'Asia/Istanbul')─┐
│ 2020-01-01 13:20:30.000 │
└────────────────────────────────────────┘
See also
- Timezone server configuration parameter.
toStartOfFiveMinutes
Rounds down a date with time to the start of the five-minute interval.
Syntax
toStartOfFiveMinutes(value)
Arguments
value
- a DateTime or DateTime64
Returned value
- The start of the five-minute interval of the given date/time
Type: DateTime
Example
SELECT
toStartOfFiveMinutes(toDateTime('2023-04-21 10:17:00')),
toStartOfFiveMinutes(toDateTime('2023-04-21 10:20:00')),
toStartOfFiveMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical
Result:
Row 1:
──────
toStartOfFiveMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:15:00
toStartOfFiveMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:20:00
toStartOfFiveMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:20:00
toStartOfTenMinutes
Rounds down a date with time to the start of the ten-minute interval.
Syntax
toStartOfTenMinutes(value)
Arguments
value
- a DateTime or DateTime64
Returned value
- The start of the ten-minute interval of the given date/time
Type: DateTime
Example
SELECT
toStartOfTenMinutes(toDateTime('2023-04-21 10:17:00')),
toStartOfTenMinutes(toDateTime('2023-04-21 10:20:00')),
toStartOfTenMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical
Result:
Row 1:
──────
toStartOfTenMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:10:00
toStartOfTenMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:20:00
toStartOfTenMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:20:00
toStartOfFifteenMinutes
Rounds down the date with time to the start of the fifteen-minute interval.
Syntax
toStartOfFifteenMinutes(value)
Arguments
value
- a DateTime or DateTime64
Returned value
- The start of the fifteen-minute interval of the given date/time
Type: DateTime
Example
SELECT
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:17:00')),
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:20:00')),
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:23:00'))
FORMAT Vertical
Result:
Row 1:
──────
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:17:00')): 2023-04-21 10:15:00
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:20:00')): 2023-04-21 10:15:00
toStartOfFifteenMinutes(toDateTime('2023-04-21 10:23:00')): 2023-04-21 10:15:00
toStartOfInterval(date_or_date_with_time, INTERVAL x unit [, time_zone])
This function generalizes other toStartOf*()
functions. For example,
toStartOfInterval(t, INTERVAL 1 year)
returns the same astoStartOfYear(t)
,toStartOfInterval(t, INTERVAL 1 month)
returns the same astoStartOfMonth(t)
,toStartOfInterval(t, INTERVAL 1 day)
returns the same astoStartOfDay(t)
,toStartOfInterval(t, INTERVAL 15 minute)
returns the same astoStartOfFifteenMinutes(t)
.
The calculation is performed relative to specific points in time:
Interval | Start |
---|---|
year | year 0 |
quarter | 1900 Q1 |
month | 1900 January |
week | 1970, 1st week (01-05) |
day | 1970-01-01 |
hour | (*) |
minute | 1970-01-01 00:00:00 |
second | 1970-01-01 00:00:00 |
millisecond | 1970-01-01 00:00:00 |
microsecond | 1970-01-01 00:00:00 |
nanosecond | 1970-01-01 00:00:00 |
(*) hour intervals are special: the calculation is always performed relative to 00:00:00 (midnight) of the current day. As a result, only hour values between 1 and 23 are useful.
See Also
toTime
Converts a date with time to a certain fixed date, while preserving the time.
toRelativeYearNum
Converts a date, or date with time, to the number of the year, starting from a certain fixed point in the past.
toRelativeQuarterNum
Converts a date, or date with time, to the number of the quarter, starting from a certain fixed point in the past.
toRelativeMonthNum
Converts a date, or date with time, to the number of the month, starting from a certain fixed point in the past.
toRelativeWeekNum
Converts a date, or date with time, to the number of the week, starting from a certain fixed point in the past.
toRelativeDayNum
Converts a date, or date with time, to the number of the day, starting from a certain fixed point in the past.
toRelativeHourNum
Converts a date, or date with time, to the number of the hour, starting from a certain fixed point in the past.
toRelativeMinuteNum
Converts a date, or date with time, to the number of the minute, starting from a certain fixed point in the past.
toRelativeSecondNum
Converts a date, or date with time, to the number of the second, starting from a certain fixed point in the past.
toISOYear
Converts a date, or date with time, to a UInt16 number containing the ISO Year number.
toISOWeek
Converts a date, or date with time, to a UInt8 number containing the ISO Week number.
toWeek
This function returns the week number for date or datetime. The two-argument form of toWeek()
enables you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the default mode is 0.
toISOWeek()
is a compatibility function that is equivalent to toWeek(date,3)
.
The following table describes how the mode argument works.
Mode | First day of week | Range | Week 1 is the first week … |
---|---|---|---|
0 | Sunday | 0-53 | with a Sunday in this year |
1 | Monday | 0-53 | with 4 or more days this year |
2 | Sunday | 1-53 | with a Sunday in this year |
3 | Monday | 1-53 | with 4 or more days this year |
4 | Sunday | 0-53 | with 4 or more days this year |
5 | Monday | 0-53 | with a Monday in this year |
6 | Sunday | 1-53 | with 4 or more days this year |
7 | Monday | 1-53 | with a Monday in this year |
8 | Sunday | 1-53 | contains January 1 |
9 | Monday | 1-53 | contains January 1 |
For mode values with a meaning of “with 4 or more days this year,” weeks are numbered according to ISO 8601:1988:
If the week containing January 1 has 4 or more days in the new year, it is week 1.
Otherwise, it is the last week of the previous year, and the next week is week 1.
For mode values with a meaning of “contains January 1”, the week contains January 1 is week 1. It does not matter how many days in the new year the week contained, even if it contained only one day. I.e. if the last week of December contains January 1 of the next year, it will be week 1 of the next year.
Syntax
toWeek(t[, mode[, time_zone]])
Alias: WEEK
Arguments
t
– Date or DateTime.mode
– Optional parameter, Range of values is [0,9], default is 0.Timezone
– Optional parameter, it behaves like any other conversion function.
The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.
Example
SELECT toDate('2016-12-27') AS date, toWeek(date) AS week0, toWeek(date,1) AS week1, toWeek(date,9) AS week9;
┌───────date─┬─week0─┬─week1─┬─week9─┐
│ 2016-12-27 │ 52 │ 52 │ 1 │
└────────────┴───────┴───────┴───────┘
toYearWeek
Returns year and week for a date. The year in the result may be different from the year in the date argument for the first and the last week of the year.
The mode argument works like the mode argument to toWeek()
. For the single-argument syntax, a mode value of 0 is used.
toISOYear()
is a compatibility function that is equivalent to intDiv(toYearWeek(date,3),100)
.
The week number returned by toYearWeek()
can be different from what the toWeek()
returns. toWeek()
always returns week number in the context of the given year, and in case toWeek()
returns 0
, toYearWeek()
returns the value corresponding to the last week of previous year. See prev_yearWeek
in example below.
Syntax
toYearWeek(t[, mode[, timezone]])
Alias: YEARWEEK
The first argument can also be specified as String in a format supported by parseDateTime64BestEffort(). Support for string arguments exists only for reasons of compatibility with MySQL which is expected by certain 3rd party tools. As string argument support may in future be made dependent on new MySQL-compatibility settings and because string parsing is generally slow, it is recommended to not use it.
Example
SELECT toDate('2016-12-27') AS date, toYearWeek(date) AS yearWeek0, toYearWeek(date,1) AS yearWeek1, toYearWeek(date,9) AS yearWeek9, toYearWeek(toDate('2022-01-01')) AS prev_yearWeek;
┌───────date─┬─yearWeek0─┬─yearWeek1─┬─yearWeek9─┬─prev_yearWeek─┐
│ 2016-12-27 │ 201652 │ 201652 │ 201701 │ 202152 │
└────────────┴───────────┴───────────┴───────────┴───────────────┘
toDaysSinceYearZero
Returns for a given date, the number of days passed since 1 January 0000 in the proleptic Gregorian calendar defined by ISO 8601. The calculation is the same as in MySQL's TO_DAYS()
function.
Syntax
toDaysSinceYearZero(date[, time_zone])
Alias: TO_DAYS
Arguments
date
— The date to calculate the number of days passed since year zero from. Date, Date32, DateTime or DateTime64.time_zone
— A String type const value or an expression represent the time zone. String types
Returned value
The number of days passed since date 0000-01-01.
Type: UInt32.
Example
SELECT toDaysSinceYearZero(toDate('2023-09-08'));
Result:
┌─toDaysSinceYearZero(toDate('2023-09-08')))─┐
│ 713569 │
└────────────────────────────────────────────┘
See Also
fromDaysSinceYearZero
Returns for a given number of days passed since 1 January 0000 the corresponding date in the proleptic Gregorian calendar defined by ISO 8601. The calculation is the same as in MySQL's FROM_DAYS()
function.
The result is undefined if it cannot be represented within the bounds of the Date type.
Syntax
fromDaysSinceYearZero(days)
Alias: FROM_DAYS
Arguments
days
— The number of days passed since year zero.
Returned value
The date corresponding to the number of days passed since year zero.
Type: Date.
Example
SELECT fromDaysSinceYearZero(739136), fromDaysSinceYearZero(toDaysSinceYearZero(toDate('2023-09-08')));
Result:
┌─fromDaysSinceYearZero(739136)─┬─fromDaysSinceYearZero(toDaysSinceYearZero(toDate('2023-09-08')))─┐
│ 2023-09-08 │ 2023-09-08 │
└───────────────────────────────┴──────────────────────────────────────────────────────────────────┘
See Also
fromDaysSinceYearZero32
Like fromDaysSinceYearZero but returns a Date32.
age
Returns the unit
component of the difference between startdate
and enddate
. The difference is calculated using a precision of 1 nanosecond.
E.g. the difference between 2021-12-29
and 2022-01-01
is 3 days for day
unit, 0 months for month
unit, 0 years for year
unit.
For an alternative to age
, see function date\_diff
.
Syntax
age('unit', startdate, enddate, [timezone])
Arguments
unit
— The type of interval for result. String. Possible values:nanosecond
,nanoseconds
,ns
microsecond
,microseconds
,us
,u
millisecond
,milliseconds
,ms
second
,seconds
,ss
,s
minute
,minutes
,mi
,n
hour
,hours
,hh
,h
day
,days
,dd
,d
week
,weeks
,wk
,ww
month
,months
,mm
,m
quarter
,quarters
,qq
,q
year
,years
,yyyy
,yy
startdate
— The first time value to subtract (the subtrahend). Date, Date32, DateTime or DateTime64.enddate
— The second time value to subtract from (the minuend). Date, Date32, DateTime or DateTime64.timezone
— Timezone name (optional). If specified, it is applied to bothstartdate
andenddate
. If not specified, timezones ofstartdate
andenddate
are used. If they are not the same, the result is unspecified. String.
Returned value
Difference between enddate
and startdate
expressed in unit
.
Type: Int.
Example
SELECT age('hour', toDateTime('2018-01-01 22:30:00'), toDateTime('2018-01-02 23:00:00'));
Result:
┌─age('hour', toDateTime('2018-01-01 22:30:00'), toDateTime('2018-01-02 23:00:00'))─┐
│ 24 │
└───────────────────────────────────────────────────────────────────────────────────┘
SELECT
toDate('2022-01-01') AS e,
toDate('2021-12-29') AS s,
age('day', s, e) AS day_age,
age('month', s, e) AS month__age,
age('year', s, e) AS year_age;
Result:
┌──────────e─┬──────────s─┬─day_age─┬─month__age─┬─year_age─┐
│ 2022-01-01 │ 2021-12-29 │ 3 │ 0 │ 0 │
└────────────┴────────────┴─────────┴────────────┴──────────┘
date_diff
Returns the count of the specified unit
boundaries crossed between the startdate
and the enddate
.
The difference is calculated using relative units, e.g. the difference between 2021-12-29
and 2022-01-01
is 3 days for unit day
(see toRelativeDayNum), 1 month for unit month
(see toRelativeMonthNum) and 1 year for unit year
(see toRelativeYearNum).
If unit week
was specified, date\_diff
assumes that weeks start on Monday. Note that this behavior is different from that of function toWeek()
in which weeks start by default on Sunday.
For an alternative to date\_diff
, see function age
.
Syntax
date_diff('unit', startdate, enddate, [timezone])
Aliases: dateDiff
, DATE_DIFF
, timestampDiff
, timestamp_diff
, TIMESTAMP_DIFF
.
Arguments
unit
— The type of interval for result. String. Possible values:nanosecond
,nanoseconds
,ns
microsecond
,microseconds
,us
,u
millisecond
,milliseconds
,ms
second
,seconds
,ss
,s
minute
,minutes
,mi
,n
hour
,hours
,hh
,h
day
,days
,dd
,d
week
,weeks
,wk
,ww
month
,months
,mm
,m
quarter
,quarters
,qq
,q
year
,years
,yyyy
,yy
startdate
— The first time value to subtract (the subtrahend). Date, Date32, DateTime or DateTime64.enddate
— The second time value to subtract from (the minuend). Date, Date32, DateTime or DateTime64.timezone
— Timezone name (optional). If specified, it is applied to bothstartdate
andenddate
. If not specified, timezones ofstartdate
andenddate
are used. If they are not the same, the result is unspecified. String.
Returned value
Difference between enddate
and startdate
expressed in unit
.
Type: Int.
Example
SELECT dateDiff('hour', toDateTime('2018-01-01 22:00:00'), toDateTime('2018-01-02 23:00:00'));
Result:
┌─dateDiff('hour', toDateTime('2018-01-01 22:00:00'), toDateTime('2018-01-02 23:00:00'))─┐
│ 25 │
└────────────────────────────────────────────────────────────────────────────────────────┘
SELECT
toDate('2022-01-01') AS e,
toDate('2021-12-29') AS s,
dateDiff('day', s, e) AS day_diff,
dateDiff('month', s, e) AS month__diff,
dateDiff('year', s, e) AS year_diff;
Result:
┌──────────e─┬──────────s─┬─day_diff─┬─month__diff─┬─year_diff─┐
│ 2022-01-01 │ 2021-12-29 │ 3 │ 1 │ 1 │
└────────────┴────────────┴──────────┴─────────────┴───────────┘
date_trunc
Truncates date and time data to the specified part of date.
Syntax
date_trunc(unit, value[, timezone])
Alias: dateTrunc
.
Arguments
unit
— The type of interval to truncate the result. String Literal. Possible values:second
minute
hour
day
week
month
quarter
year
unit
argument is case-insensitive.
value
— Date and time. DateTime or DateTime64.timezone
— Timezone name for the returned value (optional). If not specified, the function uses the timezone of thevalue
parameter. String.
Returned value
- Value, truncated to the specified part of date.
Type: DateTime.
Example
Query without timezone:
SELECT now(), date_trunc('hour', now());
Result:
┌───────────────now()─┬─date_trunc('hour', now())─┐
│ 2020-09-28 10:40:45 │ 2020-09-28 10:00:00 │
└─────────────────────┴───────────────────────────┘
Query with the specified timezone:
SELECT now(), date_trunc('hour', now(), 'Asia/Istanbul');
Result:
┌───────────────now()─┬─date_trunc('hour', now(), 'Asia/Istanbul')─┐
│ 2020-09-28 10:46:26 │ 2020-09-28 13:00:00 │
└─────────────────────┴────────────────────────────────────────────┘
See Also
date_add
Adds the time interval or date interval to the provided date or date with time.
If the addition results in a value outside the bounds of the data type, the result is undefined.
Syntax
date_add(unit, value, date)
Aliases: dateAdd
, DATE_ADD
.
Arguments
unit
— The type of interval to add. String. Possible values:second
minute
hour
day
week
month
quarter
year
value
— Value of interval to add. Int.date
— The date or date with time to whichvalue
is added. Date, Date32, DateTime or DateTime64.
Returned value
Date or date with time obtained by adding value
, expressed in unit
, to date
.
Type: Date, Date32, DateTime or DateTime64.
Example
SELECT date_add(YEAR, 3, toDate('2018-01-01'));
Result:
┌─plus(toDate('2018-01-01'), toIntervalYear(3))─┐
│ 2021-01-01 │
└───────────────────────────────────────────────┘
See Also
date_sub
Subtracts the time interval or date interval from the provided date or date with time.
If the subtraction results in a value outside the bounds of the data type, the result is undefined.
Syntax
date_sub(unit, value, date)
Aliases: dateSub
, DATE_SUB
.
Arguments
unit
— The type of interval to subtract. Note: The unit should be unquoted.Possible values:
second
minute
hour
day
week
month
quarter
year
value
— Value of interval to subtract. Int.date
— The date or date with time from whichvalue
is subtracted. Date, Date32, DateTime or DateTime64.
Returned value
Date or date with time obtained by subtracting value
, expressed in unit
, from date
.
Type: Date, Date32, DateTime or DateTime64.
Example
SELECT date_sub(YEAR, 3, toDate('2018-01-01'));
Result:
┌─minus(toDate('2018-01-01'), toIntervalYear(3))─┐
│ 2015-01-01 │
└────────────────────────────────────────────────┘
See Also
timestamp_add
Adds the specified time value with the provided date or date time value.
If the addition results in a value outside the bounds of the data type, the result is undefined.
Syntax
timestamp_add(date, INTERVAL value unit)
Aliases: timeStampAdd
, TIMESTAMP_ADD
.
Arguments
date
— Date or date with time. Date, Date32, DateTime or DateTime64.value
— Value of interval to add. Int.unit
— The type of interval to add. String. Possible values:second
minute
hour
day
week
month
quarter
year
Returned value
Date or date with time with the specified value
expressed in unit
added to date
.
Type: Date, Date32, DateTime or DateTime64.
Example
select timestamp_add(toDate('2018-01-01'), INTERVAL 3 MONTH);
Result:
┌─plus(toDate('2018-01-01'), toIntervalMonth(3))─┐
│ 2018-04-01 │
└────────────────────────────────────────────────┘
timestamp_sub
Subtracts the time interval from the provided date or date with time.
If the subtraction results in a value outside the bounds of the data type, the result is undefined.
Syntax
timestamp_sub(unit, value, date)
Aliases: timeStampSub
, TIMESTAMP_SUB
.
Arguments
unit
— The type of interval to subtract. String. Possible values:second
minute
hour
day
week
month
quarter
year
value
— Value of interval to subtract. Int.date
— Date or date with time. Date, Date32, DateTime or DateTime64.
Returned value
Date or date with time obtained by subtracting value
, expressed in unit
, from date
.
Type: Date, Date32, DateTime or DateTime64.
Example
select timestamp_sub(MONTH, 5, toDateTime('2018-12-18 01:02:03'));
Result:
┌─minus(toDateTime('2018-12-18 01:02:03'), toIntervalMonth(5))─┐
│ 2018-07-18 01:02:03 │
└──────────────────────────────────────────────────────────────┘
addDate
Adds the time interval to the provided date, date with time or String-encoded date / date with time.
If the addition results in a value outside the bounds of the data type, the result is undefined.
Syntax
addDate(date, interval)
Arguments
date
— The date or date with time to whichinterval
is added. Date, Date32, DateTime, DateTime64, or Stringinterval
— Interval to add. Interval.
Returned value
Date or date with time obtained by adding interval
to date
.
Type: Date, Date32, DateTime or DateTime64.
Example
SELECT addDate(toDate('2018-01-01'), INTERVAL 3 YEAR);
Result:
┌─addDate(toDate('2018-01-01'), toIntervalYear(3))─┐
│ 2021-01-01 │
└──────────────────────────────────────────────────┘
Alias: ADDDATE
See Also
subDate
Subtracts the time interval from the provided date, date with time or String-encoded date / date with time.
If the subtraction results in a value outside the bounds of the data type, the result is undefined.
Syntax
subDate(date, interval)
Arguments
date
— The date or date with time from whichinterval
is subtracted. Date, Date32, DateTime, DateTime64, or Stringinterval
— Interval to subtract. Interval.
Returned value
Date or date with time obtained by subtracting interval
from date
.
Type: Date, Date32, DateTime or DateTime64.
Example
SELECT subDate(toDate('2018-01-01'), INTERVAL 3 YEAR);
Result:
┌─subDate(toDate('2018-01-01'), toIntervalYear(3))─┐
│ 2015-01-01 │
└──────────────────────────────────────────────────┘
Alias: SUBDATE
See Also
now
Returns the current date and time at the moment of query analysis. The function is a constant expression.
Alias: current_timestamp
.
Syntax
now([timezone])
Arguments
timezone
— Timezone name for the returned value (optional). String.
Returned value
- Current date and time.
Type: DateTime.
Example
Query without timezone:
SELECT now();
Result:
┌───────────────now()─┐
│ 2020-10-17 07:42:09 │
└─────────────────────┘
Query with the specified timezone:
SELECT now('Asia/Istanbul');
Result:
┌─now('Asia/Istanbul')─┐
│ 2020-10-17 10:42:23 │
└──────────────────────┘
now64
Returns the current date and time with sub-second precision at the moment of query analysis. The function is a constant expression.
Syntax
now64([scale], [timezone])
Arguments
scale
- Tick size (precision): 10-precision seconds. Valid range: [ 0 : 9 ]. Typically, are used - 3 (default) (milliseconds), 6 (microseconds), 9 (nanoseconds).timezone
— Timezone name for the returned value (optional). String.
Returned value
- Current date and time with sub-second precision.
Type: DateTime64.
Example
SELECT now64(), now64(9, 'Asia/Istanbul');
Result:
┌─────────────────now64()─┬─────now64(9, 'Asia/Istanbul')─┐
│ 2022-08-21 19:34:26.196 │ 2022-08-21 22:34:26.196542766 │
└─────────────────────────┴───────────────────────────────┘
nowInBlock
Returns the current date and time at the moment of processing of each block of data. In contrast to the function now, it is not a constant expression, and the returned value will be different in different blocks for long-running queries.
It makes sense to use this function to generate the current time in long-running INSERT SELECT queries.
Syntax
nowInBlock([timezone])
Arguments
timezone
— Timezone name for the returned value (optional). String.
Returned value
- Current date and time at the moment of processing of each block of data.
Type: DateTime.
Example
SELECT
now(),
nowInBlock(),
sleep(1)
FROM numbers(3)
SETTINGS max_block_size = 1
FORMAT PrettyCompactMonoBlock
Result:
┌───────────────now()─┬────────nowInBlock()─┬─sleep(1)─┐
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:19 │ 0 │
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:20 │ 0 │
│ 2022-08-21 19:41:19 │ 2022-08-21 19:41:21 │ 0 │
└─────────────────────┴─────────────────────┴──────────┘
today
Returns the current date at moment of query analysis. It is the same as ‘toDate(now())’ and has aliases: curdate
, current_date
.
Syntax
today()
Arguments
- None
Returned value
- Current date
Type: DateTime.
Example
Query:
SELECT today() AS today, curdate() AS curdate, current_date() AS current_date FORMAT Pretty
Result:
Running the query above on the 3rd of March 2024 would have returned the following response:
┏━━━━━━━━━━━━┳━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ today ┃ curdate ┃ current_date ┃
┡━━━━━━━━━━━━╇━━━━━━━━━━━━╇━━━━━━━━━━━━━━┩
│ 2024-03-03 │ 2024-03-03 │ 2024-03-03 │
└────────────┴────────────┴──────────────┘
yesterday
Accepts zero arguments and returns yesterday’s date at one of the moments of query analysis. The same as ‘today() - 1’.
timeSlot
Rounds the time to the half hour.
toYYYYMM
Converts a date or date with time to a UInt32 number containing the year and month number (YYYY * 100 + MM). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.
This function is the opposite of function YYYYMMDDToDate()
.
Example
SELECT
toYYYYMM(now(), 'US/Eastern')
Result:
┌─toYYYYMM(now(), 'US/Eastern')─┐
│ 202303 │
└───────────────────────────────┘
toYYYYMMDD
Converts a date or date with time to a UInt32 number containing the year and month number (YYYY * 10000 + MM * 100 + DD). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.
Example
SELECT toYYYYMMDD(now(), 'US/Eastern')
Result:
┌─toYYYYMMDD(now(), 'US/Eastern')─┐
│ 20230302 │
└─────────────────────────────────┘
toYYYYMMDDhhmmss
Converts a date or date with time to a UInt64 number containing the year and month number (YYYY * 10000000000 + MM * 100000000 + DD * 1000000 + hh * 10000 + mm * 100 + ss). Accepts a second optional timezone argument. If provided, the timezone must be a string constant.
Example
SELECT toYYYYMMDDhhmmss(now(), 'US/Eastern')
Result:
┌─toYYYYMMDDhhmmss(now(), 'US/Eastern')─┐
│ 20230302112209 │
└───────────────────────────────────────┘
YYYYMMDDToDate
Converts a number containing the year, month and day number to a Date.
This function is the opposite of function toYYYYMMDD()
.
The output is undefined if the input does not encode a valid Date value.
Syntax
YYYYMMDDToDate(yyyymmdd);
Arguments
Returned value
- a date created from the arguments.
Type: Date.
Example
SELECT YYYYMMDDToDate(20230911);
Result:
┌─toYYYYMMDD(20230911)─┐
│ 2023-09-11 │
└──────────────────────┘
YYYYMMDDToDate32
Like function YYYYMMDDToDate()
but produces a Date32.
YYYYMMDDhhmmssToDateTime
Converts a number containing the year, month, day, hours, minute and second number to a DateTime.
The output is undefined if the input does not encode a valid DateTime value.
This function is the opposite of function toYYYYMMDDhhmmss()
.
Syntax
YYYYMMDDhhmmssToDateTime(yyyymmddhhmmss[, timezone]);
Arguments
yyyymmddhhmmss
- A number representing the year, month and day. Integer, Float or Decimal.timezone
- Timezone for the returned value (optional).
Returned value
- a date with time created from the arguments.
Type: DateTime.
Example
SELECT YYYYMMDDToDateTime(20230911131415);
Result:
┌──────YYYYMMDDhhmmssToDateTime(20230911131415)─┐
│ 2023-09-11 13:14:15 │
└───────────────────────────────────────────────┘
YYYYMMDDhhmmssToDateTime64
Like function YYYYMMDDhhmmssToDate()
but produces a DateTime64.
Accepts an additional, optional precision
parameter after the timezone
parameter.
addYears, addQuarters, addMonths, addWeeks, addDays, addHours, addMinutes, addSeconds, addMilliseconds, addMicroseconds, addNanoseconds
These functions add units of the interval specified by the function name to a date, a date with time or a string-encoded date / date with time. A date or date with time is returned.
Example:
WITH
toDate('2024-01-01') AS date,
toDateTime('2024-01-01 00:00:00') AS date_time,
'2024-01-01 00:00:00' AS date_time_string
SELECT
addYears(date, 1) AS add_years_with_date,
addYears(date_time, 1) AS add_years_with_date_time,
addYears(date_time_string, 1) AS add_years_with_date_time_string
┌─add_years_with_date─┬─add_years_with_date_time─┬─add_years_with_date_time_string─┐
│ 2025-01-01 │ 2025-01-01 00:00:00 │ 2025-01-01 00:00:00.000 │
└─────────────────────┴──────────────────────────┴─────────────────────────────────┘
subtractYears, subtractQuarters, subtractMonths, subtractWeeks, subtractDays, subtractHours, subtractMinutes, subtractSeconds, subtractMilliseconds, subtractMicroseconds, subtractNanoseconds
These functions subtract units of the interval specified by the function name from a date, a date with time or a string-encoded date / date with time. A date or date with time is returned.
Example:
WITH
toDate('2024-01-01') AS date,
toDateTime('2024-01-01 00:00:00') AS date_time,
'2024-01-01 00:00:00' AS date_time_string
SELECT
subtractYears(date, 1) AS subtract_years_with_date,
subtractYears(date_time, 1) AS subtract_years_with_date_time,
subtractYears(date_time_string, 1) AS subtract_years_with_date_time_string
┌─subtract_years_with_date─┬─subtract_years_with_date_time─┬─subtract_years_with_date_time_string─┐
│ 2023-01-01 │ 2023-01-01 00:00:00 │ 2023-01-01 00:00:00.000 │
└──────────────────────────┴───────────────────────────────┴──────────────────────────────────────┘
timeSlots(StartTime, Duration,[, Size])
For a time interval starting at ‘StartTime’ and continuing for ‘Duration’ seconds, it returns an array of moments in time, consisting of points from this interval rounded down to the ‘Size’ in seconds. ‘Size’ is an optional parameter set to 1800 (30 minutes) by default.
This is necessary, for example, when searching for pageviews in the corresponding session.
Accepts DateTime and DateTime64 as ’StartTime’ argument. For DateTime, ’Duration’ and ’Size’ arguments must be UInt32
. For ’DateTime64’ they must be Decimal64
.
Returns an array of DateTime/DateTime64 (return type matches the type of ’StartTime’). For DateTime64, the return value's scale can differ from the scale of ’StartTime’ --- the highest scale among all given arguments is taken.
Example:
SELECT timeSlots(toDateTime('2012-01-01 12:20:00'), toUInt32(600));
SELECT timeSlots(toDateTime('1980-12-12 21:01:02', 'UTC'), toUInt32(600), 299);
SELECT timeSlots(toDateTime64('1980-12-12 21:01:02.1234', 4, 'UTC'), toDecimal64(600.1, 1), toDecimal64(299, 0));
┌─timeSlots(toDateTime('2012-01-01 12:20:00'), toUInt32(600))─┐
│ ['2012-01-01 12:00:00','2012-01-01 12:30:00'] │
└─────────────────────────────────────────────────────────────┘
┌─timeSlots(toDateTime('1980-12-12 21:01:02', 'UTC'), toUInt32(600), 299)─┐
│ ['1980-12-12 20:56:13','1980-12-12 21:01:12','1980-12-12 21:06:11'] │
└─────────────────────────────────────────────────────────────────────────┘
┌─timeSlots(toDateTime64('1980-12-12 21:01:02.1234', 4, 'UTC'), toDecimal64(600.1, 1), toDecimal64(299, 0))─┐
│ ['1980-12-12 20:56:13.0000','1980-12-12 21:01:12.0000','1980-12-12 21:06:11.0000'] │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────┘
formatDateTime
Formats a Time according to the given Format string. Format is a constant expression, so you cannot have multiple formats for a single result column.
formatDateTime uses MySQL datetime format style, refer to https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format.
The opposite operation of this function is parseDateTime.
Alias: DATE_FORMAT
.
Syntax
formatDateTime(Time, Format[, Timezone])
Returned value(s)
Returns time and date values according to the determined format.
Replacement fields
Using replacement fields, you can define a pattern for the resulting string. “Example” column shows formatting result for 2018-01-02 22:33:44
.
Placeholder | Description | Example |
---|---|---|
%a | abbreviated weekday name (Mon-Sun) | Mon |
%b | abbreviated month name (Jan-Dec) | Jan |
%c | month as an integer number (01-12), see 'Note 3' below | 01 |
%C | year divided by 100 and truncated to integer (00-99) | 20 |
%d | day of the month, zero-padded (01-31) | 02 |
%D | Short MM/DD/YY date, equivalent to %m/%d/%y | 01/02/18 |
%e | day of the month, space-padded (1-31) | 2 |
%f | fractional second, see 'Note 1' below | 1234560 |
%F | short YYYY-MM-DD date, equivalent to %Y-%m-%d | 2018-01-02 |
%g | two-digit year format, aligned to ISO 8601, abbreviated from four-digit notation | 18 |
%G | four-digit year format for ISO week number, calculated from the week-based year defined by the ISO 8601 standard, normally useful only with %V | 2018 |
%h | hour in 12h format (01-12) | 09 |
%H | hour in 24h format (00-23) | 22 |
%i | minute (00-59) | 33 |
%I | hour in 12h format (01-12) | 10 |
%j | day of the year (001-366) | 002 |
%k | hour in 24h format (00-23), see 'Note 3' below | 14 |
%l | hour in 12h format (01-12), see 'Note 3' below | 09 |
%m | month as an integer number (01-12) | 01 |
%M | full month name (January-December), see 'Note 2' below | January |
%n | new-line character (‘’) | |
%p | AM or PM designation | PM |
%Q | Quarter (1-4) | 1 |
%r | 12-hour HH:MM AM/PM time, equivalent to %h:%i %p | 10:30 PM |
%R | 24-hour HH:MM time, equivalent to %H:%i | 22:33 |
%s | second (00-59) | 44 |
%S | second (00-59) | 44 |
%t | horizontal-tab character (’) | |
%T | ISO 8601 time format (HH:MM:SS), equivalent to %H:%i:%S | 22:33:44 |
%u | ISO 8601 weekday as number with Monday as 1 (1-7) | 2 |
%V | ISO 8601 week number (01-53) | 01 |
%w | weekday as a integer number with Sunday as 0 (0-6) | 2 |
%W | full weekday name (Monday-Sunday) | Monday |
%y | Year, last two digits (00-99) | 18 |
%Y | Year | 2018 |
%z | Time offset from UTC as +HHMM or -HHMM | -0500 |
%% | a % sign | % |
Note 1: In ClickHouse versions earlier than v23.4, %f
prints a single zero (0) if the formatted value is a Date, Date32 or DateTime (which have no fractional seconds) or a DateTime64 with a precision of 0. The previous behavior can be restored using setting formatdatetime_f_prints_single_zero = 1
.
Note 2: In ClickHouse versions earlier than v23.4, %M
prints the minute (00-59) instead of the full month name (January-December). The previous behavior can be restored using setting formatdatetime_parsedatetime_m_is_month_name = 0
.
Note 3: In ClickHouse versions earlier than v23.11, function parseDateTime()
required leading zeros for formatters %c
(month) and %l
/%k
(hour), e.g. 07
. In later versions, the leading zero may be omitted, e.g. 7
. The previous behavior can be restored using setting parsedatetime_parse_without_leading_zeros = 0
. Note that function formatDateTime()
by default still prints leading zeros for %c
and %l
/%k
to not break existing use cases. This behavior can be changed by setting formatdatetime_format_without_leading_zeros = 1
.
Example
SELECT formatDateTime(toDate('2010-01-04'), '%g')
Result:
┌─formatDateTime(toDate('2010-01-04'), '%g')─┐
│ 10 │
└────────────────────────────────────────────┘
SELECT formatDateTime(toDateTime64('2010-01-04 12:34:56.123456', 7), '%f')
Result:
┌─formatDateTime(toDateTime64('2010-01-04 12:34:56.123456', 7), '%f')─┐
│ 1234560 │
└─────────────────────────────────────────────────────────────────────┘
Additionally, the formatDateTime
function can take a third String argument containing the name of the time zone. Example: Asia/Istanbul
. In this case, the time is formatted according to the specified time zone.
Example
SELECT
now() AS ts,
time_zone,
formatDateTime(ts, '%T', time_zone) AS str_tz_time
FROM system.time_zones
WHERE time_zone LIKE 'Europe%'
LIMIT 10
┌──────────────────ts─┬─time_zone─────────┬─str_tz_time─┐
│ 2023-09-08 19:13:40 │ Europe/Amsterdam │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Andorra │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Astrakhan │ 23:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Athens │ 22:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Belfast │ 20:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Belgrade │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Berlin │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Bratislava │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Brussels │ 21:13:40 │
│ 2023-09-08 19:13:40 │ Europe/Bucharest │ 22:13:40 │
└─────────────────────┴───────────────────┴─────────────┘
See Also
formatDateTimeInJodaSyntax
Similar to formatDateTime, except that it formats datetime in Joda style instead of MySQL style. Refer to https://joda-time.sourceforge.net/apidocs/org/joda/time/format/DateTimeFormat.html.
The opposite operation of this function is parseDateTimeInJodaSyntax.
Replacement fields
Using replacement fields, you can define a pattern for the resulting string.
Placeholder | Description | Presentation | Examples |
---|---|---|---|
G | era | text | AD |
C | century of era (>=0) | number | 20 |
Y | year of era (>=0) | year | 1996 |
x | weekyear (not supported yet) | year | 1996 |
w | week of weekyear (not supported yet) | number | 27 |
e | day of week | number | 2 |
E | day of week | text | Tuesday; Tue |
y | year | year | 1996 |
D | day of year | number | 189 |
M | month of year | month | July; Jul; 07 |
d | day of month | number | 10 |
a | halfday of day | text | PM |
K | hour of halfday (0~11) | number | 0 |
h | clockhour of halfday (1~12) | number | 12 |
H | hour of day (0~23) | number | 0 |
k | clockhour of day (1~24) | number | 24 |
m | minute of hour | number | 30 |
s | second of minute | number | 55 |
S | fraction of second (not supported yet) | number | 978 |
z | time zone (short name not supported yet) | text | Pacific Standard Time; PST |
Z | time zone offset/id (not supported yet) | zone | -0800; -08:00; America/Los_Angeles |
' | escape for text | delimiter | |
'' | single quote | literal | ' |
Example
SELECT formatDateTimeInJodaSyntax(toDateTime('2010-01-04 12:34:56'), 'yyyy-MM-dd HH:mm:ss')
Result:
┌─formatDateTimeInJodaSyntax(toDateTime('2010-01-04 12:34:56'), 'yyyy-MM-dd HH:mm:ss')─┐
│ 2010-01-04 12:34:56 │
└─────────────────────────────────────────────────────────────────────────────────────────┘
dateName
Returns specified part of date.
Syntax
dateName(date_part, date)
Arguments
date_part
— Date part. Possible values: 'year', 'quarter', 'month', 'week', 'dayofyear', 'day', 'weekday', 'hour', 'minute', 'second'. String.date
— Date. Date, Date32, DateTime or DateTime64.timezone
— Timezone. Optional. String.
Returned value
- The specified part of date.
Type: String
Example
WITH toDateTime('2021-04-14 11:22:33') AS date_value
SELECT
dateName('year', date_value),
dateName('month', date_value),
dateName('day', date_value);
Result:
┌─dateName('year', date_value)─┬─dateName('month', date_value)─┬─dateName('day', date_value)─┐
│ 2021 │ April │ 14 │
└──────────────────────────────┴───────────────────────────────┴─────────────────────────────┘
monthName
Returns name of the month.
Syntax
monthName(date)
Arguments
date
— Date or date with time. Date, DateTime or DateTime64.
Returned value
- The name of the month.
Type: String
Example
WITH toDateTime('2021-04-14 11:22:33') AS date_value
SELECT monthName(date_value);
Result:
┌─monthName(date_value)─┐
│ April │
└───────────────────────┘
fromUnixTimestamp
This function converts a Unix timestamp to a calendar date and a time of a day.
It can be called in two ways:
When given a single argument of type Integer, it returns a value of type DateTime, i.e. behaves like toDateTime.
Alias: FROM_UNIXTIME
.
Example:
SELECT fromUnixTimestamp(423543535);
Result:
┌─fromUnixTimestamp(423543535)─┐
│ 1983-06-04 10:58:55 │
└──────────────────────────────┘
When given two or three arguments where the first argument is a value of type Integer, Date, Date32, DateTime or DateTime64, the second argument is a constant format string and the third argument is an optional constant time zone string, the function returns a value of type String, i.e. it behaves like formatDateTime. In this case, MySQL's datetime format style is used.
Example:
SELECT fromUnixTimestamp(1234334543, '%Y-%m-%d %R:%S') AS DateTime;
Result:
┌─DateTime────────────┐
│ 2009-02-11 14:42:23 │
└─────────────────────┘
See Also
fromUnixTimestampInJodaSyntax
Same as fromUnixTimestamp but when called in the second way (two or three arguments), the formatting is performed using Joda style instead of MySQL style.
Example:
SELECT fromUnixTimestampInJodaSyntax(1234334543, 'yyyy-MM-dd HH:mm:ss', 'UTC') AS DateTime;
Result:
┌─DateTime────────────┐
│ 2009-02-11 06:42:23 │
└─────────────────────┘
toModifiedJulianDay
Converts a Proleptic Gregorian calendar date in text form YYYY-MM-DD
to a Modified Julian Day number in Int32. This function supports date from 0000-01-01
to 9999-12-31
. It raises an exception if the argument cannot be parsed as a date, or the date is invalid.
Syntax
toModifiedJulianDay(date)
Arguments
date
— Date in text form. String or FixedString.
Returned value
- Modified Julian Day number.
Type: Int32.
Example
SELECT toModifiedJulianDay('2020-01-01');
Result:
┌─toModifiedJulianDay('2020-01-01')─┐
│ 58849 │
└───────────────────────────────────┘
toModifiedJulianDayOrNull
Similar to toModifiedJulianDay(), but instead of raising exceptions it returns NULL
.
Syntax
toModifiedJulianDayOrNull(date)
Arguments
date
— Date in text form. String or FixedString.
Returned value
- Modified Julian Day number.
Type: Nullable(Int32).
Example
SELECT toModifiedJulianDayOrNull('2020-01-01');
Result:
┌─toModifiedJulianDayOrNull('2020-01-01')─┐
│ 58849 │
└─────────────────────────────────────────┘
fromModifiedJulianDay
Converts a Modified Julian Day number to a Proleptic Gregorian calendar date in text form YYYY-MM-DD
. This function supports day number from -678941
to 2973119
(which represent 0000-01-01 and 9999-12-31 respectively). It raises an exception if the day number is outside of the supported range.
Syntax
fromModifiedJulianDay(day)
Arguments
day
— Modified Julian Day number. Any integral types.
Returned value
- Date in text form.
Type: String
Example
SELECT fromModifiedJulianDay(58849);
Result:
┌─fromModifiedJulianDay(58849)─┐
│ 2020-01-01 │
└──────────────────────────────┘
fromModifiedJulianDayOrNull
Similar to fromModifiedJulianDayOrNull(), but instead of raising exceptions it returns NULL
.
Syntax
fromModifiedJulianDayOrNull(day)
Arguments
day
— Modified Julian Day number. Any integral types.
Returned value
- Date in text form.
Type: Nullable(String)
Example
SELECT fromModifiedJulianDayOrNull(58849);
Result:
┌─fromModifiedJulianDayOrNull(58849)─┐
│ 2020-01-01 │
└────────────────────────────────────┘
toUTCTimestamp
Convert DateTime/DateTime64 type value from other time zone to UTC timezone timestamp
Syntax
toUTCTimestamp(time_val, time_zone)
Arguments
time_val
— A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 typestime_zone
— A String type const value or an expression represent the time zone. String types
Returned value
- DateTime/DateTime64 in text form
Example
SELECT toUTCTimestamp(toDateTime('2023-03-16'), 'Asia/Shanghai');
Result:
┌─toUTCTimestamp(toDateTime('2023-03-16'),'Asia/Shanghai')┐
│ 2023-03-15 16:00:00 │
└─────────────────────────────────────────────────────────┘
fromUTCTimestamp
Convert DateTime/DateTime64 type value from UTC timezone to other time zone timestamp
Syntax
fromUTCTimestamp(time_val, time_zone)
Arguments
time_val
— A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 typestime_zone
— A String type const value or an expression represent the time zone. String types
Returned value
- DateTime/DateTime64 in text form
Example
SELECT fromUTCTimestamp(toDateTime64('2023-03-16 10:00:00', 3), 'Asia/Shanghai');
Result:
┌─fromUTCTimestamp(toDateTime64('2023-03-16 10:00:00',3),'Asia/Shanghai')─┐
│ 2023-03-16 18:00:00.000 │
└─────────────────────────────────────────────────────────────────────────┘
timeDiff
Returns the difference between two dates or dates with time values. The difference is calculated in units of seconds. It is same as dateDiff
and was added only for MySQL support. dateDiff
is preferred.
Syntax
timeDiff(first_datetime, second_datetime)
*Arguments**
first_datetime
— A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 typessecond_datetime
— A DateTime/DateTime64 type const value or an expression . DateTime/DateTime64 types
Returned value
The difference between two dates or dates with time values in seconds.
Example
Query:
timeDiff(toDateTime64('1927-01-01 00:00:00', 3), toDate32('1927-01-02'));
Result:
┌─timeDiff(toDateTime64('1927-01-01 00:00:00', 3), toDate32('1927-01-02'))─┐
│ 86400 │
└──────────────────────────────────────────────────────────────────────────┘