Incidentally, I just realized that this is one of the rare years that Shavuot and the Christian Pentecost occur on the same day: May 24.
Does anyone know why Shavuot is now celebrated over two days? (Technically, it starts on the evening of May 23 and lasts until the evening of May 25.) Was it always celebrated over two days? (If so, that’s really wild, because it solves the connundrum I mentioned about Pentecost being celebrated 50 days after Easter, instead of 50 days after Passover; if the first Pentecost started on 50 days after Good Friday, the events of Acts 2 could actually have happened on a Sunday.)
Nope! Every Jewish holiday is celebrated on two days, to prevent disagreement on which day they should be celebrated. Some Jews felt that you should start counting a day as in Genesis, where God works for a day, evening comes and morning follows, thus from morning to morning. Most followed the evening-to-evening definition now so much associated with Jewish observances. Thus, there were two observances of passover: on Thursday AND on Friday! This is fully in synch with the fact that Jesus celebrated Passover on Thursday night, but was the passover offering on Friday afternoon!
(I’ve read many Christians on this forum argue that either the death of Jesus was on a Thursday or the Resurrection was on a Monday.)