To add time to a date use the DATEADD Transact-SQL statement.
DATEADD (datepart , number, date )
The date parts can be:
| datepart | Abbreviations |
|---|---|
| year | yy, yyyy |
| quarter | qq, q |
| month | mm, m |
| dayofyear | dy, y |
| day | dd, d |
| week | wk, ww |
| weekday | dw, w |
| hour | hh |
| minute | mi, n |
| second | ss, s |
| millisecond | ms |
| microsecond | mcs |
| nanosecond | ns |
For example:
SELECT DATEADD(dd, 12, "29 March 1964")
To get the date at midnight you can use the following:
SELECT DATEADD(dd,0, DATEDIFF(dd,0, GETDATE())) as date_at_midnight
See http://msdn.microsoft.com/en-us/library/ms186819.aspx for details.