Try ISDATE()
function in SQL Server. If 1, select valid date. If 0 selects invalid dates.
SELECT cast(CONVERT(varchar, LoginTime, 101) as datetime)
FROM AuditTrail
WHERE ISDATE(LoginTime) = 1
EDIT :
As per your update i need to extract the date only and remove the time, then you could simply use the inner CONVERT
SELECT CONVERT(VARCHAR, LoginTime, 101) FROM AuditTrail
or
SELECT LEFT(LoginTime,10) FROM AuditTrail
EDIT 2 :
The major reason for the error will be in your date in WHERE clause.ie,
SELECT cast(CONVERT(varchar, LoginTime, 101) as datetime)
FROM AuditTrail
where CAST(CONVERT(VARCHAR, LoginTime, 101) AS DATE) <=
CAST('06/18/2012' AS DATE)
will be different from
SELECT cast(CONVERT(varchar, LoginTime, 101) as datetime)
FROM AuditTrail
where CAST(CONVERT(VARCHAR, LoginTime, 101) AS DATE) <=
CAST('18/06/2012' AS DATE)
CONCLUSION
In EDIT 2 the first query tries to filter in mm/dd/yyyy
format, while the second query tries to filter in dd/mm/yyyy
format. Either of them will fail and throws error
The conversion of a varchar data type to a datetime data type resulted
in an out-of-range value.
So please make sure to filter date either with mm/dd/yyyy
or with dd/mm/yyyy
format, whichever works in your db.