Even in the Communist system Easter Monday was public Holiday. The Monday after Pentecost became Holiday recently, to replacing the former May 1st as public Holiday.
For the Church until the Divino Afflatu Reform both Monday and Tuesday and both after Easter and Pentecost were Festa Feriata: Holy days of obligation. So were all the feast of Apostles, and the major feasts of the Blessed Virgin. After 1911 most of them were advised feast, so the Church celebrated them as the Holy days of obligation, but it was not obligatory, the churches were half full.
We went to Church on the day after Christmas and the Monday after Easter.