Beginning of new Hebrew month of Nisan. Nisan (sometimes transliterated Nissan) is the 1st month of the Hebrew year. rresponds to March or April on the Gregorian calendar
Haftarah: Isaiah 66:1 - 66:24
https://www.hebcal.com/holidays/rosh-chodesh-nisan-2022?utm_source=js&utm_medium=icalendar