DATE_ADD

Complete DATE_ADD() reference: DATE_ADD(date, INTERVAL expr unit) syntax, negative interval support, unit keywords (DAY/MONTH/YEAR), and return types.

Syntax

DATE_ADD(date,INTERVAL expr unit)

Description

Performs date arithmetic. The date argument specifies the starting date or datetime value. expr is an expression specifying the interval value to be added to the starting date. expr is a string; it may start with a "-" for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted. See Date and Time Units for a complete list of permitted units.

The result type of DATE_ADD() is determined as follows:

• if the first argument is of the type DATETIME, the function returns DATETIME ;

• if the first argument is DATE and the interval uses HOUR or smaller units, the function returns DATETIME ;

• if the first argument is DATE and the interval uses DAY or larger units, the function returns DATE ;

• similarly, if the first argument is TIME and the interval uses DAY or smaller units the function returns TIME, if the interval uses anything larger, the function returns DATETIME ;

• if the first argument isn't a temporal type, the function returns a string.

Examples

SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND;
+-------------------------------------------+
| '2008-12-31 23:59:59' + INTERVAL 1 SECOND |
+-------------------------------------------+
| 2009-01-01 00:00:00                       |
+-------------------------------------------+

SELECT INTERVAL 1 DAY + '2008-12-31';
+-------------------------------+
| INTERVAL 1 DAY + '2008-12-31' |
+-------------------------------+
| 2009-01-01                    |
+-------------------------------+

SELECT '2005-01-01' - INTERVAL 1 SECOND;
+----------------------------------+
| '2005-01-01' - INTERVAL 1 SECOND |
+----------------------------------+
| 2004-12-31 23:59:59              |
+----------------------------------+

SELECT DATE_ADD('2000-12-31 23:59:59', INTERVAL 1 SECOND);
+----------------------------------------------------+
| DATE_ADD('2000-12-31 23:59:59', INTERVAL 1 SECOND) |
+----------------------------------------------------+
| 2001-01-01 00:00:00                                |
+----------------------------------------------------+

SELECT DATE_ADD('2010-12-31 23:59:59', INTERVAL 1 DAY);
+-------------------------------------------------+
| DATE_ADD('2010-12-31 23:59:59', INTERVAL 1 DAY) |
+-------------------------------------------------+
| 2011-01-01 23:59:59                             |
+-------------------------------------------------+

SELECT DATE_ADD('2100-12-31 23:59:59', INTERVAL '1:1' MINUTE_SECOND);
+---------------------------------------------------------------+
| DATE_ADD('2100-12-31 23:59:59', INTERVAL '1:1' MINUTE_SECOND) |
+---------------------------------------------------------------+
| 2101-01-01 00:01:00                                           |
+---------------------------------------------------------------+

SELECT DATE_ADD('1900-01-01 00:00:00', INTERVAL '-1 10' DAY_HOUR);
+------------------------------------------------------------+
| DATE_ADD('1900-01-01 00:00:00', INTERVAL '-1 10' DAY_HOUR) |
+------------------------------------------------------------+
| 1899-12-30 14:00:00                                        |
+------------------------------------------------------------+

SELECT DATE_ADD('1992-12-31 23:59:59.000002', INTERVAL '1.999999' SECOND_MICROSECOND);
+--------------------------------------------------------------------------------+
| DATE_ADD('1992-12-31 23:59:59.000002', INTERVAL '1.999999' SECOND_MICROSECOND) |
+--------------------------------------------------------------------------------+
| 1993-01-01 00:00:01.000001                                                     |
+--------------------------------------------------------------------------------+

See Also

• DATE_SUB

• ADD_MONTHS

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