SQL Server/T-SQL Tutorial/Date Functions/ISDATE

select ISDATE("2002-09-30")

3> select ISDATE("2002-09-30")
4> GO
-----------
          1
(1 rows affected)
1>

select ISDATE("2002-09-31")

3> select ISDATE("2002-09-31")
4> GO
-----------
          0
(1 rows affected)

select ISDATE("23:59:59")

2> select ISDATE("23:59:59")
3> GO
-----------
          1
(1 rows affected)
1>

select ISDATE("23:99:99")

3> select ISDATE("23:99:99")
4> GO
-----------
          0
(1 rows affected)