Friday evening, July 5, 2024, at 6:57 PM EDT, will be the new Moon, when the Moon passes between the Earth and the Sun and will not be visible from the Earth. The day of or the day after the New Moon marks the start of the new month for most lunisolar calendars. Saturday, July 6 will be the start of the sixth month of the Chinese year of the Dragon. Sundown on July 6 will mark the start of Tammuz in the Hebrew calendar. In the Islamic calendar the months traditionally start with the first sighting of the waxing crescent Moon. Many Muslim communities now follow the Umm al-Qura Calendar of Saudi Arabia, which uses astronomical calculations to start months in a more predictable way. Using this calendar, sundown on Saturday, July 6, will probably mark Al-Hijra, the Islamic New Year and the beginning of the month of Muharram, although Muharram is one of four months for which the calendar dates may be adjusted by the religious authorities of Saudi Arabia after actual sightings of the lunar crescent. Al-Hijra is a public holiday in many Muslim countries. Customs vary, but most include observing the day quietly and practicing gratitude. Muharram is one of the four sacred months during which warfare is forbidden.