A little more information. The date '1900-01-01 00:00:00.000' is sometimes referred to as the 0 (zero) date. If you run select cast(0 as datetime) you will return '1900-01-01'. Knowing this helps wih completing a variety date calculations. To see some, go here:

http://www.sqlservercentral.com/blogs/lynnpettis/2009/03/25/some-common-date-routines/