Date and Time Functions • TIMESTAMPADD( unit , interval , datetime_expr ) • TIMESTAMPDIFF( unit , datetime_expr1 , datetime_expr2 ) • TIME_FORMAT( time , format ) • TIME_TO_SEC( time ) • TO_DAYS( date ) 2165 mysql>  SELECT TO_DAYS(950501); -> 728779 mysql>  SELECT TIME_TO_SEC(’22:23:00’); -> 80580 mysql>  SELECT TIME_TO_SEC(’00:39:38’); -> 2378 Returns the  time  argument, converted to seconds. Given a date  date , returns a day number (the number of days since year 0). If the  time  value contains an hour part that is greater than  23 , the  %H  and  %k  hour format specifiers produce a value larger than the usual range of  0..23 . The other hour format specifiers produce the hour value modulo 12. This is used like the  DATE_FORMAT()  function, but the  format  string may contain format specifiers only for hours, minutes, seconds, and microseconds. Other specifiers produce a  NULL  value or  0 . mysql>  SELECT TIME_FORMAT(’100:00:00’, ’%H %k %h %I %l’); -> ’100 100 04 04 4’ 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 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’ Adds the integer expression  interval  to the date or datetime expression  datetime_expr . The unit for  interval  is given by the  unit  argument, which should be one of the following values: MICROSECOND  (microseconds),  SECOND ,  MINUTE ,  HOUR ,  DAY ,  WEEK ,  MONTH ,  QUARTER , or  YEAR . The  unit  value may be specified using one of keywords as shown, or with a prefix of  SQL_TSI_ . For example,  DAY  and  SQL_TSI_DAY  both are legal. Returns  datetime_expr2 − datetime_expr1 , where  datetime_expr1  and  datetime_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 the  unit  argument. The legal values for  unit  are the same as those listed in the description of the  TIMESTAMPADD()  function. The 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. Note