It's Whitsunday--no, Pentecost--wait-Whitsunday--
Potāto, potăto, it's the 50th and final day of Easter. From the CCDP bulletin: The Feast of Pentecost was formerly called Whitsunday because it was a day on which many were baptized, hence many white garments. It is the day on which the church celebrates the outpouring of the Holy Spirit on the apostles.