Beginning of new Hebrew month of Iyyar. Iyyar (somtimes transliterated Iyar) is the 2nd month of the Hebrew year. Corresponds to April or May on the Gregorian calendar
Haftarah: Isaiah 66:1 - 66:24

https://www.hebcal.com/holidays/rosh-chodesh-iyyar-2023?utm_source=js&utm_medium=icalendar