to the fifteenth day of the month or the phenomenon of lunar alignment, not to the seventh day of a week. However, different studies found evidence that the biblical sabbath indeed sometimes had a monthly, rather than weekly, meaning.

Connection to Sabbath observance has been suggested by the designation of the seventh, fourteenth, nineteenth, twenty-first, and twenty-eighth days of a lunar month in an Assyrian religious calendar as 'holy day', also called 'evil days' (meaning "unsuitable" for prohibited activities). The prohibitions