Just a sample site of a possible usage of DateTimeExtensions nuget package.
January 01 Anul Nou
January 02 A doua zi de Anul Nou
May 01 Ziua Muncii
May 02 Vinerea Mare
May 04 Paștele
May 05 Paștele
June 22 Rusaliile
June 23 A doua zi de Rusaliile
December 25 Craciun
December 26 A doua zi de Craciun
December 31 Ajunul de anul nou