Just a sample site of a possible usage of DateTimeExtensions nuget package.
January 01 New Year
March 01 AshWednesday
April 14 Good Friday
April 17 Easter Monday
May 23 Labor Day
August 01 Emancipation Day
August 07 Independence Day Observed
October 16 National Heroes Day
December 25 Christmas
December 26 Boxing Day
DateTimeExtensions DateTimeExtensions