--- { "title": "datediff", "language": "en" } --- # datediff ## Description ### Syntax 'DATETIME DATEDIFF (DATETIME expr1,DATETIME expr2)' Expr1 - expr2 is calculated and the result is accurate to the sky. Expr1 and expr2 parameters are valid date or date/time expressions. Note: Only the date part of the value participates in the calculation. ### example ``` mysql> select datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME)); +-----------------------------------------------------------------------------------+ | datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME)) | +-----------------------------------------------------------------------------------+ | 1 | +-----------------------------------------------------------------------------------+ mysql> select datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME)); +-----------------------------------------------------------------------------------+ | datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME)) | +-----------------------------------------------------------------------------------+ | -31 | +-----------------------------------------------------------------------------------+ ``` ## keyword DATEDIFF