How does SqlDateTime do its precision reduction

Question

Consider the following program:

DateTime dateTime = new DateTime(634546165144647370);
SqlDateTime sqlDateTime = new SqlDateTime(dateTime);

Console.WriteLine         


        

Answer 1

SQL Server DATETIME has an accuracy of 3.33ms - therefore, you cannot get all possible values, and there's a good chance .464 was just such a value.

On SQL Server 2008, you could use DATETIME2 or TIME(x) datatypes which have an accuracy to 100ns - that should be plenty enough for "regular" use