DateTime.MinValue and SqlDateTime overflow

Very simple avoid using DateTime.MinValue use System.Data.SqlTypes.SqlDateTime.MinValue instead.

Although it is an old question, another solution is to use datetime2 for the database column. MSDN Link

Well... its quite simple to get a SQL min date

DateTime sqlMinDateAsNetDateTime = System.Data.SqlTypes.SqlDateTime.MinValue.Value;

Basically, don't use DateTime.MinValue to represent a missing value. You can't use DateTime.MinValue in a SQL Server DateTime field, as SQL Server has a minimum value of the start of 1753.

Instead, make your BirthDate property a Nullable<DateTime> (aka DateTime?), and set it to null when you don't have a value. Also make sure your database field is nullable. Then you just need to make sure that that null ends up as a NULL value in the database. Exactly how you do that will depend on your data access, which you haven't told us anything about.