A Blessed and Happy Easter to all! He is risen!
We are in the Octave of Easter; each day in the Octave is a First Class Feast. Fr Z puts it well:
An Octave is a period when time is stops. We rest in the mystery of the great feast we celebrated, since one day simply isn’t enough. We are continuing Easter through all the days of the Octave. In the older rite we say Mass with the Gloria, Sequence and Creed. In the Novus Ordo we use the Gloria, and can use the Sequence, though we are not obliged to use the Creed. There are restrictions on votive Masses for the dead, etc. We say in the Te Deum in the office every day during the Octave.
The Octave of Easter will end this Sunday, April 12th, on Divine Mercy Sunday.