This section describes the functions that can be used to manipulate temporal values. See Section 11.2, “Date and Time Data Types”, for a description of the range of values each date and time type has and the valid formats in which values may be specified.
Table 12.11 Date and Time Functions
Name | Description |
---|---|
ADDDATE() |
Add time values (intervals) to a date value |
ADDTIME() |
Add time |
CONVERT_TZ() |
Convert from one time zone to another |
CURDATE() |
Return the current date |
CURRENT_DATE() , CURRENT_DATE |
Synonyms for CURDATE() |
CURRENT_TIME() , CURRENT_TIME |
Synonyms for CURTIME() |
CURRENT_TIMESTAMP() , CURRENT_TIMESTAMP |
Synonyms for NOW() |
CURTIME() |
Return the current time |
DATE() |
Extract the date part of a date or datetime expression |
DATE_ADD() |
Add time values (intervals) to a date value |
DATE_FORMAT() |
Format date as specified |
DATE_SUB() |
Subtract a time value (interval) from a date |
DATEDIFF() |
Subtract two dates |
DAY() |
Synonym for DAYOFMONTH() |
DAYNAME() |
Return the name of the weekday |
DAYOFMONTH() |
Return the day of the month (0-31) |
DAYOFWEEK() |
Return the weekday index of the argument |
DAYOFYEAR() |
Return the day of the year (1-366) |
EXTRACT() |
Extract part of a date |
FROM_DAYS() |
Convert a day number to a date |
FROM_UNIXTIME() |
Format Unix timestamp as a date |
GET_FORMAT() |
Return a date format string |
HOUR() |
Extract the hour |
LAST_DAY |
Return the last day of the month for the argument |
LOCALTIME() , LOCALTIME |
Synonym for NOW() |
LOCALTIMESTAMP , LOCALTIMESTAMP() |
Synonym for NOW() |
MAKEDATE() |
Create a date from the year and day of year |
MAKETIME() |
Create time from hour, minute, second |
MICROSECOND() |
Return the microseconds from argument |
MINUTE() |
Return the minute from the argument |
MONTH() |
Return the month from the date passed |
MONTHNAME() |
Return the name of the month |
NOW() |
Return the current date and time |
PERIOD_ADD() |
Add a period to a year-month |
PERIOD_DIFF() |
Return the number of months between periods |
QUARTER() |
Return the quarter from a date argument |
SEC_TO_TIME() |
Converts seconds to 'hh:mm:ss' format |
SECOND() |
Return the second (0-59) |
STR_TO_DATE() |
Convert a string to a date |
SUBDATE() |
Synonym for DATE_SUB() when invoked with three arguments |
SUBTIME() |
Subtract times |
SYSDATE() |
Return the time at which the function executes |
TIME() |
Extract the time portion of the expression passed |
TIME_FORMAT() |
Format as time |
TIME_TO_SEC() |
Return the argument converted to seconds |
TIMEDIFF() |
Subtract time |
TIMESTAMP() |
With a single argument, this function returns the date or datetime expression; with two arguments, the sum of the arguments |
TIMESTAMPADD() |
Add an interval to a datetime expression |
TIMESTAMPDIFF() |
Return the difference of two datetime expressions, using the units specified |
TO_DAYS() |
Return the date argument converted to days |
TO_SECONDS() |
Return the date or datetime argument converted to seconds since Year 0 |
UNIX_TIMESTAMP() |
Return a Unix timestamp |
UTC_DATE() |
Return the current UTC date |
UTC_TIME() |
Return the current UTC time |
UTC_TIMESTAMP() |
Return the current UTC date and time |
WEEK() |
Return the week number |
WEEKDAY() |
Return the weekday index |
WEEKOFYEAR() |
Return the calendar week of the date (1-53) |
YEAR() |
Return the year |
YEARWEEK() |
Return the year and week |
Here is an example that uses date functions. The following query
selects all rows with a date_col
value
from within the last 30 days:
mysql> SELECT something FROM tbl_name
-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col;
The query also selects rows with dates that lie in the future.
Functions that expect date values usually accept datetime values and ignore the time part. Functions that expect time values usually accept datetime values and ignore the date part.
Functions that return the current date or time each are evaluated
only once per query at the start of query execution. This means
that multiple references to a function such as
NOW()
within a single query always
produce the same result. (For our purposes, a single query also
includes a call to a stored program (stored routine, trigger, or
event) and all subprograms called by that program.) This principle
also applies to CURDATE()
,
CURTIME()
,
UTC_DATE()
,
UTC_TIME()
,
UTC_TIMESTAMP()
, and to any of
their synonyms.
The CURRENT_TIMESTAMP()
,
CURRENT_TIME()
,
CURRENT_DATE()
, and
FROM_UNIXTIME()
functions return
values in the current session time zone, which is available as the
session value of the time_zone
system variable. In addition,
UNIX_TIMESTAMP()
assumes that its
argument is a datetime value in the session time zone. See
Section 5.1.13, “MySQL Server Time Zone Support”.
Some date functions can be used with “zero” dates or
incomplete dates such as '2001-11-00'
, whereas
others cannot. Functions that extract parts of dates typically
work with incomplete dates and thus can return 0 when you might
otherwise expect a nonzero value. For example:
mysql> SELECT DAYOFMONTH('2001-11-00'), MONTH('2005-00-00');
-> 0, 0
Other functions expect complete dates and return
NULL
for incomplete dates. These include
functions that perform date arithmetic or that map parts of dates
to names. For example:
mysql> SELECT DATE_ADD('2006-05-00',INTERVAL 1 DAY);
-> NULL
mysql> SELECT DAYNAME('2006-05-00');
-> NULL
Several functions are strict when passed a
DATE()
function value as their
argument and reject incomplete dates with a day part of zero:
CONVERT_TZ()
,
DATE_ADD()
,
DATE_SUB()
,
DAYOFYEAR()
,
TIMESTAMPDIFF()
,
TO_DAYS()
,
TO_SECONDS()
,
WEEK()
,
WEEKDAY()
,
WEEKOFYEAR()
,
YEARWEEK()
.
Fractional seconds for TIME
,
DATETIME
, and TIMESTAMP
values are supported, with up to microsecond precision. Functions
that take temporal arguments accept values with fractional
seconds. Return values from temporal functions include fractional
seconds as appropriate.
ADDDATE(
,date
,INTERVALexpr
unit
)ADDDATE(
expr
,days
)When invoked with the
INTERVAL
form of the second argument,ADDDATE()
is a synonym forDATE_ADD()
. The related functionSUBDATE()
is a synonym forDATE_SUB()
. For information on theINTERVAL
unit
argument, see Temporal Intervals.mysql> SELECT DATE_ADD('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02' mysql> SELECT ADDDATE('2008-01-02', INTERVAL 31 DAY); -> '2008-02-02'
When invoked with the
days
form of the second argument, MySQL treats it as an integer number of days to be added toexpr
.mysql> SELECT ADDDATE('2008-01-02', 31); -> '2008-02-02'
ADDTIME()
addsexpr2
toexpr1
and returns the result.expr1
is a time or datetime expression, andexpr2
is a time expression.mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999', '1 1:1:1.000002'); -> '2008-01-02 01:01:01.000001' mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998'); -> '03:00:01.999997'
CONVERT_TZ()
converts a datetime valuedt
from the time zone given byfrom_tz
to the time zone given byto_tz
and returns the resulting value. Time zones are specified as described in Section 5.1.13, “MySQL Server Time Zone Support”. This function returnsNULL
if the arguments are invalid.If the value falls out of the supported range of the
TIMESTAMP
type when converted fromfrom_tz
to UTC, no conversion occurs. TheTIMESTAMP
range is described in Section 11.2.1, “Date and Time Data Type Syntax”.mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET'); -> '2004-01-01 13:00:00' mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00'); -> '2004-01-01 22:00:00'
NoteTo use named time zones such as
'MET'
or'Europe/Amsterdam'
, the time zone tables must be properly set up. For instructions, see Section 5.1.13, “MySQL Server Time Zone Support”.Returns the current date as a value in
'
orYYYY-MM-DD
'YYYYMMDD
format, depending on whether the function is used in string or numeric context.mysql> SELECT CURDATE(); -> '2008-06-13' mysql> SELECT CURDATE() + 0; -> 20080613
CURRENT_DATE
andCURRENT_DATE()
are synonyms forCURDATE()
.CURRENT_TIME
,CURRENT_TIME([
fsp
])CURRENT_TIME
andCURRENT_TIME()
are synonyms forCURTIME()
.CURRENT_TIMESTAMP
,CURRENT_TIMESTAMP([
fsp
])CURRENT_TIMESTAMP
andCURRENT_TIMESTAMP()
are synonyms forNOW()
.Returns the current time as a value in
'hh:mm:ss'
orhhmmss
format, depending on whether the function is used in string or numeric context. The value is expressed in the session time zone.If the
fsp
argument is given to specify a fractional seconds precision from 0 to 6, the return value includes a fractional seconds part of that many digits.mysql> SELECT CURTIME(); -> '23:50:26' mysql> SELECT CURTIME() + 0; -> 235026.000000
Extracts the date part of the date or datetime expression
expr
.mysql> SELECT DATE('2003-12-31 01:02:03'); -> '2003-12-31'
DATEDIFF()
returnsexpr1
−expr2
expressed as a value in days from one date to the other.expr1
andexpr2
are date or date-and-time expressions. Only the date parts of the values are used in the calculation.mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30'); -> 1 mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31'); -> -31
DATE_ADD(
,date
,INTERVALexpr
unit
)DATE_SUB(
date
,INTERVALexpr
unit
)These functions perform date arithmetic. The
date
argument specifies the starting date or datetime value.expr
is an expression specifying the interval value to be added or subtracted from the starting date.expr
is evaluated as a string; it may start with a-
for negative intervals.unit
is a keyword indicating the units in which the expression should be interpreted.For more information about temporal interval syntax, including a full list of
unit
specifiers, the expected form of theexpr
argument for eachunit
value, and rules for operand interpretation in temporal arithmetic, see Temporal Intervals.The return value depends on the arguments:
DATE
if thedate
argument is aDATE
value and your calculations involve onlyYEAR
,MONTH
, andDAY
parts (that is, no time parts).DATETIME
if the first argument is aDATETIME
(orTIMESTAMP
) value, or if the first argument is aDATE
and theunit
value usesHOURS
,MINUTES
, orSECONDS
.String otherwise.
To ensure that the result is
DATETIME
, you can useCAST()
to convert the first argument toDATETIME
.mysql> SELECT DATE_ADD('2018-05-01',INTERVAL 1 DAY); -> '2018-05-02' mysql> SELECT DATE_SUB('2018-05-01',INTERVAL 1 YEAR); -> '2017-05-01' mysql> SELECT DATE_ADD('2020-12-31 23:59:59', -> INTERVAL 1 SECOND); -> '2021-01-01 00:00:00' mysql> SELECT DATE_ADD('2018-12-31 23:59:59', -> INTERVAL 1 DAY); -> '2019-01-01 23:59:59' mysql> SELECT DATE_ADD('2100-12-31 23:59:59', -> INTERVAL '1:1' MINUTE_SECOND); -> '2101-01-01 00:01:00' mysql> SELECT DATE_SUB('2025-01-01 00:00:00', -> INTERVAL '1 1:1:1' DAY_SECOND); -> '2024-12-30 22:58:59' mysql> SELECT DATE_ADD('1900-01-01 00:00:00', -> INTERVAL '-1 10' DAY_HOUR); -> '1899-12-30 14:00:00' mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY); -> '1997-12-02' mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002', -> INTERVAL '1.999999' SECOND_MICROSECOND); -> '1993-01-01 00:00:01.000001'
When adding a
MONTH
interval to aDATE
orDATETIME
value, and the resulting date includes a day that does not exist in the given month, the day is adjusted to the last day of the month, as shown here:mysql> SELECT DATE_ADD('2024-03-30', INTERVAL 1 MONTH) AS d1, > DATE_ADD('2024-03-31', INTERVAL 1 MONTH) AS d2; +------------+------------+ | d1 | d2 | +------------+------------+ | 2024-04-30 | 2024-04-30 | +------------+------------+ 1 row in set (0.00 sec)
Formats the
date
value according to theformat
string.The specifiers shown in the following table may be used in the
format
string. The%
character is required before format specifier characters. The specifiers apply to other functions as well:STR_TO_DATE()
,TIME_FORMAT()
,UNIX_TIMESTAMP()
.Specifier Description %a
Abbreviated weekday name ( Sun
..Sat
)%b
Abbreviated month name ( Jan
..Dec
)%c
Month, numeric ( 0
..12
)%D
Day of the month with English suffix ( 0th
,1st
,2nd
,3rd
, …)%d
Day of the month, numeric ( 00
..31
)%e
Day of the month, numeric ( 0
..31
)%f
Microseconds ( 000000
..999999
)%H
Hour ( 00
..23
)%h
Hour ( 01
..12
)%I
Hour ( 01
..12
)%i
Minutes, numeric ( 00
..59
)%j
Day of year ( 001
..366
)%k
Hour ( 0
..23
)%l
Hour ( 1
..12
)%M
Month name ( January
..December
)%m
Month, numeric ( 00
..12
)%p
AM
orPM
%r
Time, 12-hour ( hh:mm:ss
followed byAM
orPM
)%S
Seconds ( 00
..59
)%s
Seconds ( 00
..59
)%T
Time, 24-hour ( hh:mm:ss
)%U
Week ( 00
..53
), where Sunday is the first day of the week;WEEK()
mode 0%u
Week ( 00
..53
), where Monday is the first day of the week;WEEK()
mode 1%V
Week ( 01
..53
), where Sunday is the first day of the week;WEEK()
mode 2; used with%X
%v
Week ( 01
..53
), where Monday is the first day of the week;WEEK()
mode 3; used with%x
%W
Weekday name ( Sunday
..Saturday
)%w
Day of the week ( 0
=Sunday..6
=Saturday)%X
Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x
Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
%Y
Year, numeric, four digits %y
Year, numeric (two digits) %%
A literal %
character%
x
x
, for any “x
” not listed aboveRanges for the month and day specifiers begin with zero due to the fact that MySQL permits the storing of incomplete dates such as
'2014-00-00'
.The language used for day and month names and abbreviations is controlled by the value of the
lc_time_names
system variable (Section 10.16, “MySQL Server Locale Support”).For the
%U
,%u
,%V
, and%v
specifiers, see the description of theWEEK()
function for information about the mode values. The mode affects how week numbering occurs.DATE_FORMAT()
returns a string with a character set and collation given bycharacter_set_connection
andcollation_connection
so that it can return month and weekday names containing non-ASCII characters.mysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y'); -> 'Sunday October 2009' mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s'); -> '22:23:00' mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00', -> '%D %y %a %d %m %b %j'); -> '4th 00 Thu 04 10 Oct 277' mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00', -> '%H %k %I %r %T %S %w'); -> '22 22 10 10:23:00 PM 22:23:00 00 6' mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V'); -> '1998 52' mysql> SELECT DATE_FORMAT('2006-06-00', '%d'); -> '00'
DATE_SUB(
date
,INTERVALexpr
unit
)See the description for
DATE_ADD()
.DAY()
is a synonym forDAYOFMONTH()
.Returns the name of the weekday for
date
. The language used for the name is controlled by the value of thelc_time_names
system variable (Section 10.16, “MySQL Server Locale Support”).mysql> SELECT DAYNAME('2007-02-03'); -> 'Saturday'
Returns the day of the month for
date
, in the range1
to31
, or0
for dates such as'0000-00-00'
or'2008-00-00'
that have a zero day part.mysql> SELECT DAYOFMONTH('2007-02-03'); -> 3
Returns the weekday index for
date
(1
= Sunday,2
= Monday, …,7
= Saturday). These index values correspond to the ODBC standard.mysql> SELECT DAYOFWEEK('2007-02-03'); -> 7
Returns the day of the year for
date
, in the range1
to366
.mysql> SELECT DAYOFYEAR('2007-02-03'); -> 34
The
EXTRACT()
function uses the same kinds ofunit
specifiers asDATE_ADD()
orDATE_SUB()
, but extracts parts from the date rather than performing date arithmetic. For information on theunit
argument, see Temporal Intervals.mysql> SELECT EXTRACT(YEAR FROM '2019-07-02'); -> 2019 mysql> SELECT EXTRACT(YEAR_MONTH FROM '2019-07-02 01:02:03'); -> 201907 mysql> SELECT EXTRACT(DAY_MINUTE FROM '2019-07-02 01:02:03'); -> 20102 mysql> SELECT EXTRACT(MICROSECOND -> FROM '2003-01-02 10:30:00.000123'); -> 123
Given a day number
N
, returns aDATE
value.mysql> SELECT FROM_DAYS(730669); -> '2000-07-03'
Use
FROM_DAYS()
with caution on old dates. It is not intended for use with values that precede the advent of the Gregorian calendar (1582). See Section 11.2.8, “What Calendar Is Used By MySQL?”.FROM_UNIXTIME(
unix_timestamp
[,format
])Returns a representation of
unix_timestamp
as a datetime or character string value. The value returned is expressed using the session time zone. (Clients can set the session time zone as described in Section 5.1.13, “MySQL Server Time Zone Support”.)unix_timestamp
is an internal timestamp value representing seconds since'1970-01-01 00:00:00'
UTC, such as produced by theUNIX_TIMESTAMP()
function.If
format
is omitted, this function returns aDATETIME
value.If
unix_timestamp
is an integer, the fractional seconds precision of theDATETIME
is zero. Whenunix_timestamp
is a decimal value, the fractional seconds precision of theDATETIME
is the same as the precision of the decimal value, up to a maximum of 6. Whenunix_timestamp
is a floating point number, the fractional seconds precision of the datetime is 6.format
is used to format the result in the same way as the format string used for theDATE_FORMAT()
function. Ifformat
is supplied, the value returned is aVARCHAR
.mysql> SELECT FROM_UNIXTIME(1447430881); -> '2015-11-13 10:08:01' mysql> SELECT FROM_UNIXTIME(1447430881) + 0; -> 20151113100801 mysql> SELECT FROM_UNIXTIME(1447430881, -> '%Y %D %M %h:%i:%s %x'); -> '2015 13th November 10:08:01 2015'
NoteIf you use
UNIX_TIMESTAMP()
andFROM_UNIXTIME()
to convert between values in a non-UTC time zone and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For details, see the description of theUNIX_TIMESTAMP()
function.GET_FORMAT({DATE|TIME|DATETIME}, {'EUR'|'USA'|'JIS'|'ISO'|'INTERNAL'})
Returns a format string. This function is useful in combination with the
DATE_FORMAT()
and theSTR_TO_DATE()
functions.The possible values for the first and second arguments result in several possible format strings (for the specifiers used, see the table in the
DATE_FORMAT()
function description). ISO format refers to ISO 9075, not ISO 8601.Function Call Result GET_FORMAT(DATE,'USA')
'%m.%d.%Y'
GET_FORMAT(DATE,'JIS')
'%Y-%m-%d'
GET_FORMAT(DATE,'ISO')
'%Y-%m-%d'
GET_FORMAT(DATE,'EUR')
'%d.%m.%Y'
GET_FORMAT(DATE,'INTERNAL')
'%Y%m%d'
GET_FORMAT(DATETIME,'USA')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'JIS')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'ISO')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'EUR')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'INTERNAL')
'%Y%m%d%H%i%s'
GET_FORMAT(TIME,'USA')
'%h:%i:%s %p'
GET_FORMAT(TIME,'JIS')
'%H:%i:%s'
GET_FORMAT(TIME,'ISO')
'%H:%i:%s'
GET_FORMAT(TIME,'EUR')
'%H.%i.%s'
GET_FORMAT(TIME,'INTERNAL')
'%H%i%s'
TIMESTAMP
can also be used as the first argument toGET_FORMAT()
, in which case the function returns the same values as forDATETIME
.mysql> SELECT DATE_FORMAT('2003-10-03',GET_FORMAT(DATE,'EUR')); -> '03.10.2003' mysql> SELECT STR_TO_DATE('10.31.2003',GET_FORMAT(DATE,'USA')); -> '2003-10-31'
Returns the hour for
time
. The range of the return value is0
to23
for time-of-day values. However, the range ofTIME
values actually is much larger, soHOUR
can return values greater than23
.mysql> SELECT HOUR('10:05:03'); -> 10 mysql> SELECT HOUR('272:59:59'); -> 272
Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns
NULL
if the argument is invalid.mysql> SELECT LAST_DAY('2003-02-05'); -> '2003-02-28' mysql> SELECT LAST_DAY('2004-02-05'); -> '2004-02-29' mysql> SELECT LAST_DAY('2004-01-01 01:01:01'); -> '2004-01-31' mysql> SELECT LAST_DAY('2003-03-32'); -> NULL
LOCALTIME
andLOCALTIME()
are synonyms forNOW()
.LOCALTIMESTAMP
,LOCALTIMESTAMP([
fsp
])LOCALTIMESTAMP
andLOCALTIMESTAMP()
are synonyms forNOW()
.Returns a date, given year and day-of-year values.
dayofyear
must be greater than 0 or the result isNULL
.mysql> SELECT MAKEDATE(2011,31), MAKEDATE(2011,32); -> '2011-01-31', '2011-02-01' mysql> SELECT MAKEDATE(2011,365), MAKEDATE(2014,365); -> '2011-12-31', '2014-12-31' mysql> SELECT MAKEDATE(2011,0); -> NULL
Returns a time value calculated from the
hour
,minute
, andsecond
arguments.The
second
argument can have a fractional part.mysql> SELECT MAKETIME(12,15,30); -> '12:15:30'
Returns the microseconds from the time or datetime expression
expr
as a number in the range from0
to999999
.mysql> SELECT MICROSECOND('12:00:00.123456'); -> 123456 mysql> SELECT MICROSECOND('2019-12-31 23:59:59.000010'); -> 10
Returns the minute for
time
, in the range0
to59
.mysql> SELECT MINUTE('2008-02-03 10:05:03'); -> 5
Returns the month for
date
, in the range1
to12
for January to December, or0
for dates such as'0000-00-00'
or'2008-00-00'
that have a zero month part.mysql> SELECT MONTH('2008-02-03'); -> 2
Returns the full name of the month for
date
. The language used for the name is controlled by the value of thelc_time_names
system variable (Section 10.16, “MySQL Server Locale Support”).mysql> SELECT MONTHNAME('2008-02-03'); -> 'February'
Returns the current date and time as a value in
'
orYYYY-MM-DD hh:mm:ss
'YYYYMMDDhhmmss
format, depending on whether the function is used in string or numeric context. The value is expressed in the session time zone.If the
fsp
argument is given to specify a fractional seconds precision from 0 to 6, the return value includes a fractional seconds part of that many digits.mysql> SELECT NOW(); -> '2007-12-15 23:50:26' mysql> SELECT NOW() + 0; -> 20071215235026.000000
NOW()
returns a constant time that indicates the time at which the statement began to execute. (Within a stored function or trigger,NOW()
returns the time at which the function or triggering statement began to execute.) This differs from the behavior forSYSDATE()
, which returns the exact time at which it executes.mysql> SELECT NOW(), SLEEP(2), NOW(); +---------------------+----------+---------------------+ | NOW() | SLEEP(2) | NOW() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:36 | 0 | 2006-04-12 13:47:36 | +---------------------+----------+---------------------+ mysql> SELECT SYSDATE(), SLEEP(2), SYSDATE(); +---------------------+----------+---------------------+ | SYSDATE() | SLEEP(2) | SYSDATE() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:44 | 0 | 2006-04-12 13:47:46 | +---------------------+----------+---------------------+
In addition, the
SET TIMESTAMP
statement affects the value returned byNOW()
but not bySYSDATE()
. This means that timestamp settings in the binary log have no effect on invocations ofSYSDATE()
. Setting the timestamp to a nonzero value causes each subsequent invocation ofNOW()
to return that value. Setting the timestamp to zero cancels this effect so thatNOW()
once again returns the current date and time.See the description for
SYSDATE()
for additional information about the differences between the two functions.Adds
N
months to periodP
(in the formatYYMM
orYYYYMM
). Returns a value in the formatYYYYMM
.NoteThe period argument
P
is not a date value.mysql> SELECT PERIOD_ADD(200801,2); -> 200803
Returns the number of months between periods
P1
andP2
.P1
andP2
should be in the formatYYMM
orYYYYMM
. Note that the period argumentsP1
andP2
are not date values.mysql> SELECT PERIOD_DIFF(200802,200703); -> 11
Returns the quarter of the year for
date
, in the range1
to4
.mysql> SELECT QUARTER('2008-04-01'); -> 2
Returns the second for
time
, in the range0
to59
.mysql> SELECT SECOND('10:05:03'); -> 3
Returns the
seconds
argument, converted to hours, minutes, and seconds, as aTIME
value. The range of the result is constrained to that of theTIME
data type. A warning occurs if the argument corresponds to a value outside that range.mysql> SELECT SEC_TO_TIME(2378); -> '00:39:38' mysql> SELECT SEC_TO_TIME(2378) + 0; -> 3938
This is the inverse of the
DATE_FORMAT()
function. It takes a stringstr
and a format stringformat
.STR_TO_DATE()
returns aDATETIME
value if the format string contains both date and time parts, or aDATE
orTIME
value if the string contains only date or time parts. Ifstr
orformat
isNULL
, the function returnsNULL
. If the date, time, or datetime value extracted fromstr
cannot be parsed according to the rules followed by the server,STR_TO_DATE()
returnsNULL
and produces a warning.The server scans
str
attempting to matchformat
to it. The format string can contain literal characters and format specifiers beginning with%
. Literal characters informat
must match literally instr
. Format specifiers informat
must match a date or time part instr
. For the specifiers that can be used informat
, see theDATE_FORMAT()
function description.mysql> SELECT STR_TO_DATE('01,5,2013','%d,%m,%Y'); -> '2013-05-01' mysql> SELECT STR_TO_DATE('May 1, 2013','%M %d,%Y'); -> '2013-05-01'
Scanning starts at the beginning of
str
and fails ifformat
is found not to match. Extra characters at the end ofstr
are ignored.mysql> SELECT STR_TO_DATE('a09:30:17','a%h:%i:%s'); -> '09:30:17' mysql> SELECT STR_TO_DATE('a09:30:17','%h:%i:%s'); -> NULL mysql> SELECT STR_TO_DATE('09:30:17a','%h:%i:%s'); -> '09:30:17'
Unspecified date or time parts have a value of 0, so incompletely specified values in
str
produce a result with some or all parts set to 0:mysql> SELECT STR_TO_DATE('abc','abc'); -> '0000-00-00' mysql> SELECT STR_TO_DATE('9','%m'); -> '0000-09-00' mysql> SELECT STR_TO_DATE('9','%s'); -> '00:00:09'
Range checking on the parts of date values is as described in Section 11.2.2, “The DATE, DATETIME, and TIMESTAMP Types”. This means, for example, that “zero” dates or dates with part values of 0 are permitted unless the SQL mode is set to disallow such values.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y'); -> '0000-00-00' mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y'); -> '2004-04-31'
If the
NO_ZERO_DATE
SQL mode is enabled, zero dates are disallowed. In that case,STR_TO_DATE()
returnsNULL
and generates a warning:mysql> SET sql_mode = ''; mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y'); +---------------------------------------+ | STR_TO_DATE('00/00/0000', '%m/%d/%Y') | +---------------------------------------+ | 0000-00-00 | +---------------------------------------+ mysql> SET sql_mode = 'NO_ZERO_DATE'; mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y'); +---------------------------------------+ | STR_TO_DATE('00/00/0000', '%m/%d/%Y') | +---------------------------------------+ | NULL | +---------------------------------------+ mysql> SHOW WARNINGS\G *************************** 1. row *************************** Level: Warning Code: 1411 Message: Incorrect datetime value: '00/00/0000' for function str_to_date
Prior to MySQL 5.7.44, it was possible to pass an invalid date string such as
'2021-11-31'
to this function. In MySQL 5.7.44 and later,STR_TO_DATE()
performs complete range checking and raises an error if the date after conversion would be invalid.NoteYou cannot use format
"%X%V"
to convert a year-week string to a date because the combination of a year and week does not uniquely identify a year and month if the week crosses a month boundary. To convert a year-week to a date, you should also specify the weekday:mysql> SELECT STR_TO_DATE('200442 Monday', '%X%V %W'); -> '2004-10-18'
You should also be aware that, for dates and the date portions of datetime values,
STR_TO_DATE()
checks (only) the individual year, month, and day of month values for validity. More precisely, this means that the year is checked to be sure that it is in the range 0-9999 inclusive, the month is checked to ensure that it is in the range 1-12 inclusive, and the day of month is checked to make sure that it is in the range 1-31 inclusive, but the server does not check the values in combination. For example,SELECT STR_TO_DATE('23-2-31', '%Y-%m-%d')
returns2023-02-31
. Enabling or disabling theALLOW_INVALID_DATES
server SQL mode has no effect on this behavior. See Section 11.2.2, “The DATE, DATETIME, and TIMESTAMP Types”, for more information.SUBDATE(
,date
,INTERVALexpr
unit
)SUBDATE(
expr
,days
)When invoked with the
INTERVAL
form of the second argument,SUBDATE()
is a synonym forDATE_SUB()
. For information on theINTERVAL
unit
argument, see the discussion forDATE_ADD()
.mysql> SELECT DATE_SUB('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02' mysql> SELECT SUBDATE('2008-01-02', INTERVAL 31 DAY); -> '2007-12-02'
The second form enables the use of an integer value for
days
. In such cases, it is interpreted as the number of days to be subtracted from the date or datetime expressionexpr
.mysql> SELECT SUBDATE('2008-01-02 12:00:00', 31); -> '2007-12-02 12:00:00'
SUBTIME()
returnsexpr1
−expr2
expressed as a value in the same format asexpr1
.expr1
is a time or datetime expression, andexpr2
is a time expression.mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002'); -> '2007-12-30 22:58:58.999997' mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998'); -> '-00:59:59.999999'
Returns the current date and time as a value in
'
orYYYY-MM-DD hh:mm:ss
'YYYYMMDDhhmmss
format, depending on whether the function is used in string or numeric context.If the
fsp
argument is given to specify a fractional seconds precision from 0 to 6, the return value includes a fractional seconds part of that many digits.SYSDATE()
returns the time at which it executes. This differs from the behavior forNOW()
, which returns a constant time that indicates the time at which the statement began to execute. (Within a stored function or trigger,NOW()
returns the time at which the function or triggering statement began to execute.)mysql> SELECT NOW(), SLEEP(2), NOW(); +---------------------+----------+---------------------+ | NOW() | SLEEP(2) | NOW() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:36 | 0 | 2006-04-12 13:47:36 | +---------------------+----------+---------------------+ mysql> SELECT SYSDATE(), SLEEP(2), SYSDATE(); +---------------------+----------+---------------------+ | SYSDATE() | SLEEP(2) | SYSDATE() | +---------------------+----------+---------------------+ | 2006-04-12 13:47:44 | 0 | 2006-04-12 13:47:46 | +---------------------+----------+---------------------+
In addition, the
SET TIMESTAMP
statement affects the value returned byNOW()
but not bySYSDATE()
. This means that timestamp settings in the binary log have no effect on invocations ofSYSDATE()
.Because
SYSDATE()
can return different values even within the same statement, and is not affected bySET TIMESTAMP
, it is nondeterministic and therefore unsafe for replication if statement-based binary logging is used. If that is a problem, you can use row-based logging.Alternatively, you can use the
--sysdate-is-now
option to causeSYSDATE()
to be an alias forNOW()
. This works if the option is used on both the source and the replica.The nondeterministic nature of
SYSDATE()
also means that indexes cannot be used for evaluating expressions that refer to it.Extracts the time part of the time or datetime expression
expr
and returns it as a string.This function is unsafe for statement-based replication. A warning is logged if you use this function when
binlog_format
is set toSTATEMENT
.mysql> SELECT TIME('2003-12-31 01:02:03'); -> '01:02:03' mysql> SELECT TIME('2003-12-31 01:02:03.000123'); -> '01:02:03.000123'
TIMEDIFF()
returnsexpr1
−expr2
expressed as a time value.expr1
andexpr2
are strings which are converted toTIME
orDATETIME
expressions; these must be of the same type following conversion.The result returned by
TIMEDIFF()
is limited to the range allowed forTIME
values. Alternatively, you can use either of the functionsTIMESTAMPDIFF()
andUNIX_TIMESTAMP()
, both of which return integers.mysql> SELECT TIMEDIFF('2000:01:01 00:00:00', -> '2000:01:01 00:00:00.000001'); -> '-00:00:00.000001' mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001', -> '2008-12-30 01:01:01.000002'); -> '46:58:57.999999'
TIMESTAMP(
,expr
)TIMESTAMP(
expr1
,expr2
)With a single argument, this function returns the date or datetime expression
expr
as a datetime value. With two arguments, it adds the time expressionexpr2
to the date or datetime expressionexpr1
and returns the result as a datetime value.mysql> SELECT TIMESTAMP('2003-12-31'); -> '2003-12-31 00:00:00' mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00'); -> '2004-01-01 00:00:00'
TIMESTAMPADD(
unit
,interval
,datetime_expr
)Adds the integer expression
interval
to the date or datetime expressiondatetime_expr
. The unit forinterval
is given by theunit
argument, which should be one of the following values:MICROSECOND
(microseconds),SECOND
,MINUTE
,HOUR
,DAY
,WEEK
,MONTH
,QUARTER
, orYEAR
.The
unit
value may be specified using one of keywords as shown, or with a prefix ofSQL_TSI_
. For example,DAY
andSQL_TSI_DAY
both are legal.mysql> SELECT TIMESTAMPADD(MINUTE,1,'2003-01-02'); -> '2003-01-02 00:01:00' mysql> SELECT TIMESTAMPADD(WEEK,1,'2003-01-02'); -> '2003-01-09'
When adding a
MONTH
interval to aDATE
orDATETIME
value, and the resulting date includes a day that does not exist in the given month, the day is adjusted to the last day of the month, as shown here:mysql> SELECT TIMESTAMPADD(MONTH, 1, DATE '2024-03-30') AS t1, > TIMESTAMPADD(MONTH, 1, DATE '2024-03-31') AS t2; +------------+------------+ | t1 | t2 | +------------+------------+ | 2024-04-30 | 2024-04-30 | +------------+------------+ 1 row in set (0.00 sec)
TIMESTAMPDIFF(
unit
,datetime_expr1
,datetime_expr2
)Returns
datetime_expr2
−datetime_expr1
, wheredatetime_expr1
anddatetime_expr2
are date or datetime expressions. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part'00:00:00'
where necessary. The unit for the result (an integer) is given by theunit
argument. The legal values forunit
are the same as those listed in the description of theTIMESTAMPADD()
function.mysql> SELECT TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01'); -> 3 mysql> SELECT TIMESTAMPDIFF(YEAR,'2002-05-01','2001-01-01'); -> -1 mysql> SELECT TIMESTAMPDIFF(MINUTE,'2003-02-01','2003-05-01 12:05:55'); -> 128885
NoteThe order of the date or datetime arguments for this function is the opposite of that used with the
TIMESTAMP()
function when invoked with 2 arguments.This is used like the
DATE_FORMAT()
function, but theformat
string may contain format specifiers only for hours, minutes, seconds, and microseconds. Other specifiers produce aNULL
value or0
.If the
time
value contains an hour part that is greater than23
, the%H
and%k
hour format specifiers produce a value larger than the usual range of0..23
. The other hour format specifiers produce the hour value modulo 12.mysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l'); -> '100 100 04 04 4'
Returns the
time
argument, converted to seconds.mysql> SELECT TIME_TO_SEC('22:23:00'); -> 80580 mysql> SELECT TIME_TO_SEC('00:39:38'); -> 2378
Given a date
date
, returns a day number (the number of days since year 0).mysql> SELECT TO_DAYS(950501); -> 728779 mysql> SELECT TO_DAYS('2007-10-07'); -> 733321
TO_DAYS()
is not intended for use with values that precede the advent of the Gregorian calendar (1582), because it does not take into account the days that were lost when the calendar was changed. For dates before 1582 (and possibly a later year in other locales), results from this function are not reliable. See Section 11.2.8, “What Calendar Is Used By MySQL?”, for details.Remember that MySQL converts two-digit year values in dates to four-digit form using the rules in Section 11.2, “Date and Time Data Types”. For example,
'2008-10-07'
and'08-10-07'
are seen as identical dates:mysql> SELECT TO_DAYS('2008-10-07'), TO_DAYS('08-10-07'); -> 733687, 733687
In MySQL, the zero date is defined as
'0000-00-00'
, even though this date is itself considered invalid. This means that, for'0000-00-00'
and'0000-01-01'
,TO_DAYS()
returns the values shown here:mysql> SELECT TO_DAYS('0000-00-00'); +-----------------------+ | to_days('0000-00-00') | +-----------------------+ | NULL | +-----------------------+ 1 row in set, 1 warning (0.00 sec) mysql> SHOW WARNINGS; +---------+------+----------------------------------------+ | Level | Code | Message | +---------+------+----------------------------------------+ | Warning | 1292 | Incorrect datetime value: '0000-00-00' | +---------+------+----------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT TO_DAYS('0000-01-01'); +-----------------------+ | to_days('0000-01-01') | +-----------------------+ | 1 | +-----------------------+ 1 row in set (0.00 sec)
This is true whether or not the
ALLOW_INVALID_DATES
SQL server mode is enabled.Given a date or datetime
expr
, returns the number of seconds since the year 0. Ifexpr
is not a valid date or datetime value, returnsNULL
.mysql> SELECT TO_SECONDS(950501); -> 62966505600 mysql> SELECT TO_SECONDS('2009-11-29'); -> 63426672000 mysql> SELECT TO_SECONDS('2009-11-29 13:43:32'); -> 63426721412 mysql> SELECT TO_SECONDS( NOW() ); -> 63426721458
Like
TO_DAYS()
,TO_SECONDS()
is not intended for use with values that precede the advent of the Gregorian calendar (1582), because it does not take into account the days that were lost when the calendar was changed. For dates before 1582 (and possibly a later year in other locales), results from this function are not reliable. See Section 11.2.8, “What Calendar Is Used By MySQL?”, for details.Like
TO_DAYS()
,TO_SECONDS()
, converts two-digit year values in dates to four-digit form using the rules in Section 11.2, “Date and Time Data Types”.In MySQL, the zero date is defined as
'0000-00-00'
, even though this date is itself considered invalid. This means that, for'0000-00-00'
and'0000-01-01'
,TO_SECONDS()
returns the values shown here:mysql> SELECT TO_SECONDS('0000-00-00'); +--------------------------+ | TO_SECONDS('0000-00-00') | +--------------------------+ | NULL | +--------------------------+ 1 row in set, 1 warning (0.00 sec) mysql> SHOW WARNINGS; +---------+------+----------------------------------------+ | Level | Code | Message | +---------+------+----------------------------------------+ | Warning | 1292 | Incorrect datetime value: '0000-00-00' | +---------+------+----------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT TO_SECONDS('0000-01-01'); +--------------------------+ | TO_SECONDS('0000-01-01') | +--------------------------+ | 86400 | +--------------------------+ 1 row in set (0.00 sec)
This is true whether or not the
ALLOW_INVALID_DATES
SQL server mode is enabled.If
UNIX_TIMESTAMP()
is called with nodate
argument, it returns a Unix timestamp representing seconds since'1970-01-01 00:00:00'
UTC.If
UNIX_TIMESTAMP()
is called with adate
argument, it returns the value of the argument as seconds since'1970-01-01 00:00:00'
UTC. The server interpretsdate
as a value in the session time zone and converts it to an internal Unix timestamp value in UTC. (Clients can set the session time zone as described in Section 5.1.13, “MySQL Server Time Zone Support”.) Thedate
argument may be aDATE
,DATETIME
, orTIMESTAMP
string, or a number inYYMMDD
,YYMMDDhhmmss
,YYYYMMDD
, orYYYYMMDDhhmmss
format. If the argument includes a time part, it may optionally include a fractional seconds part.The return value is an integer if no argument is given or the argument does not include a fractional seconds part, or
DECIMAL
if an argument is given that includes a fractional seconds part.When the
date
argument is aTIMESTAMP
column,UNIX_TIMESTAMP()
returns the internal timestamp value directly, with no implicit “string-to-Unix-timestamp” conversion.The valid range of argument values is the same as for the
TIMESTAMP
data type:'1970-01-01 00:00:01.000000'
UTC to'2038-01-19 03:14:07.999999'
UTC. If you pass an out-of-range date toUNIX_TIMESTAMP()
, it returns0
.mysql> SELECT UNIX_TIMESTAMP(); -> 1447431666 mysql> SELECT UNIX_TIMESTAMP('2015-11-13 10:20:19'); -> 1447431619 mysql> SELECT UNIX_TIMESTAMP('2015-11-13 10:20:19.012'); -> 1447431619.012
If you use
UNIX_TIMESTAMP()
andFROM_UNIXTIME()
to convert between values in a non-UTC time zone and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For example, due to conventions for local time zone changes such as Daylight Saving Time (DST), it is possible forUNIX_TIMESTAMP()
to map two values that are distinct in a non-UTC time zone to the same Unix timestamp value.FROM_UNIXTIME()
maps that value back to only one of the original values. Here is an example, using values that are distinct in theMET
time zone:mysql> SET time_zone = 'MET'; mysql> SELECT UNIX_TIMESTAMP('2005-03-27 03:00:00'); +---------------------------------------+ | UNIX_TIMESTAMP('2005-03-27 03:00:00') | +---------------------------------------+ | 1111885200 | +---------------------------------------+ mysql> SELECT UNIX_TIMESTAMP('2005-03-27 02:00:00'); +---------------------------------------+ | UNIX_TIMESTAMP('2005-03-27 02:00:00') | +---------------------------------------+ | 1111885200 | +---------------------------------------+ mysql> SELECT FROM_UNIXTIME(1111885200); +---------------------------+ | FROM_UNIXTIME(1111885200) | +---------------------------+ | 2005-03-27 03:00:00 | +---------------------------+
NoteTo use named time zones such as
'MET'
or'Europe/Amsterdam'
, the time zone tables must be properly set up. For instructions, see Section 5.1.13, “MySQL Server Time Zone Support”.If you want to subtract
UNIX_TIMESTAMP()
columns, you might want to cast them to signed integers. See Section 12.10, “Cast Functions and Operators”.Returns the current UTC date as a value in
'
orYYYY-MM-DD
'YYYYMMDD
format, depending on whether the function is used in string or numeric context.mysql> SELECT UTC_DATE(), UTC_DATE() + 0; -> '2003-08-14', 20030814
Returns the current UTC time as a value in
'hh:mm:ss'
orhhmmss
format, depending on whether the function is used in string or numeric context.If the
fsp
argument is given to specify a fractional seconds precision from 0 to 6, the return value includes a fractional seconds part of that many digits.mysql> SELECT UTC_TIME(), UTC_TIME() + 0; -> '18:07:53', 180753.000000
UTC_TIMESTAMP
,UTC_TIMESTAMP([
fsp
])Returns the current UTC date and time as a value in
'
orYYYY-MM-DD hh:mm:ss
'YYYYMMDDhhmmss
format, depending on whether the function is used in string or numeric context.If the
fsp
argument is given to specify a fractional seconds precision from 0 to 6, the return value includes a fractional seconds part of that many digits.mysql> SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0; -> '2003-08-14 18:08:04', 20030814180804.000000
This function returns the week number for
date
. The two-argument form ofWEEK()
enables you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from0
to53
or from1
to53
. If themode
argument is omitted, the value of thedefault_week_format
system variable is used. See Section 5.1.7, “Server System Variables”.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 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.
mysql> SELECT WEEK('2008-02-20'); -> 7 mysql> SELECT WEEK('2008-02-20',0); -> 7 mysql> SELECT WEEK('2008-02-20',1); -> 8 mysql> SELECT WEEK('2008-12-31',1); -> 53
If a date falls in the last week of the previous year, MySQL returns
0
if you do not use2
,3
,6
, or7
as the optionalmode
argument:mysql> SELECT YEAR('2000-01-01'), WEEK('2000-01-01',0); -> 2000, 0
One might argue that
WEEK()
should return52
because the given date actually occurs in the 52nd week of 1999.WEEK()
returns0
instead so that the return value is “the week number in the given year.” This makes use of theWEEK()
function reliable when combined with other functions that extract a date part from a date.If you prefer a result evaluated with respect to the year that contains the first day of the week for the given date, use
0
,2
,5
, or7
as the optionalmode
argument.mysql> SELECT WEEK('2000-01-01',2); -> 52
Alternatively, use the
YEARWEEK()
function:mysql> SELECT YEARWEEK('2000-01-01'); -> 199952 mysql> SELECT MID(YEARWEEK('2000-01-01'),5,2); -> '52'
Returns the weekday index for
date
(0
= Monday,1
= Tuesday, …6
= Sunday).mysql> SELECT WEEKDAY('2008-02-03 22:23:00'); -> 6 mysql> SELECT WEEKDAY('2007-11-06'); -> 1
Returns the calendar week of the date as a number in the range from
1
to53
.WEEKOFYEAR()
is a compatibility function that is equivalent toWEEK(
.date
,3)mysql> SELECT WEEKOFYEAR('2008-02-20'); -> 8
Returns the year for
date
, in the range1000
to9999
, or0
for the “zero” date.mysql> SELECT YEAR('1987-01-01'); -> 1987
YEARWEEK(
,date
)YEARWEEK(
date
,mode
)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 exactly like themode
argument toWEEK()
. For the single-argument syntax, amode
value of 0 is used. UnlikeWEEK()
, the value ofdefault_week_format
does not influenceYEARWEEK()
.mysql> SELECT YEARWEEK('1987-01-01'); -> 198652
The week number is different from what the
WEEK()
function would return (0
) for optional arguments0
or1
, asWEEK()
then returns the week in the context of the given year.