I used this update
but it returns like this
Mar 29 200
it was fine on the first time? I don't know what's wrong?
The code that Denis provided, is only formatting the way that you are seeing the data, not the way that is stored.
So, in essence, your update - removed the time portion of the date setting it to midnight 00:00:00.
When you want to select the data back, you need to use the same conversion:
to display it in the format you want to see it in