The Hebrew month used to begin when two witnesses swore they had seen the new crescent, and the news was carried across the country by hilltop bonfires.

The court in Jerusalem questioned the witnesses, declared the month, and beacons were lit ridge to ridge so distant communities knew which day the festivals fell on. Rivals lighting false fires is the reason given for switching to messengers, and eventually to calculation. Rosh Chodesh is still marked every month.