Start of month of Sivan on the Hebrew calendar. Sivan (??????) is the 3rd month of the Hebrew year, has 30 days, and corresponds to May or June on the Gregorian calendar. ????? ???????, transliterated Rosh Chodesh or Rosh Hodesh, is a minor holiday that occurs at the beginning of every month in the Hebrew calendar. It is marked by the birth of a new moon

Torah: Numbers 28:1-15

https://hebcal.com/h/rosh-chodesh-sivan-2028?uc=ical-jewish-holidays-all