Just a sample site of a possible usage of DateTimeExtensions nuget package.
January 01 New Year
March 05 AshWednesday
April 18 Good Friday
April 21 Easter Monday
May 23 Labor Day
August 01 Emancipation Day
August 06 Independence Day
October 20 National Heroes Day
December 25 Christmas
December 26 Boxing Day
DateTimeExtensions DateTimeExtensions