The Calendar
What the atlas records for this date, across the traditions it covers.
Already Underway
Feast / celebration
The fifty days from Easter Sunday to Pentecost, kept as a single festal season
Day 4 of 50
This Week In Space and Astronomy History
Dates for the Hebrew and Islamic calendars are the tabular reckoning, which is what a printed calendar prints. Communities that begin a month on a sighted crescent may differ by a day, and differ from one another by place.