Rosh Chodesh May 2025. Rosh chodesh iyar ראש חודש אייר [when a hebrew month has 30 days rosh chodesh is traditionally celebrated over two days — the 30th of the old month and 1st of the new month.] Reform congregations generally observe rosh chodesh for one day, on the first day of the hebrew month.

Rosh chodesh iyyar for hebrew year 5785 begins at sundown on sunday, 27 april 2025 and ends at nightfall on tuesday, 29 april 2025. 10 shevat / february 8.