When:
June 10, 2021 all-day
2021-06-10T00:00:00+02:00
2021-06-11T00:00:00+02:00

Beginning of new Hebrew month of Tamuz. Tamuz (sometimes transliterated Tammuz) is the 4th month of the Hebrew year. Corresponds to June or July on the Gregorian calendar

https://www.hebcal.com/holidays/rosh-chodesh-tamuz-2021?utm_source=js&utm_medium=icalendar