I am not certain about what precisely you are trying to do, but I think this SQL function will help you:
SELECT DATEADD(day,-1,'2013-04-01 16:25:00.250')
The above will give you 2013-03-31 16:25:00.250
.
It takes you back exactly one day and works on any standard date-time or date format.
Try running this command and see if it gives you what you are looking for:
SELECT DATEADD(day,-1,@CreatedDate)