The dateadd function adds an interval (specified as a integer) to a date you specify. For example, if the publication dates of all the books in the titles table slipped three days, you could get the new publication dates with this statement:
select dateadd(day, 3, pubdate) from titles
------------------- Jun 15 1986 12:00AM Jun 12 1988 12:00AM Jul 3 1985 12:00AM Jun 25 1987 12:00AM Jun 12 1989 12:00AM Jun 21 1985 12:00AM Jul 6 1997 1:43PM Jul 3 1986 12:00AM Jun 15 1987 12:00AM Jul 6 1997 1:43PM Oct 24 1990 12:00AM Jun 18 1989 12:00AM Oct 8 1990 12:00AM Jun 15 1988 12:00AM Jun 15 1988 12:00AM Oct 24 1990 12:00AM Jun 15 1985 12:00AM Jun 15 1987 12:00AM (18 rows affected)
If the date argument is given as a smalldatetime, the result is also a smalldatetime. You can use dateadd to add seconds or milliseconds to a smalldatetime, but it is meaningful only if the result date returned by dateadd changes by at least one minute.
