Numbers 9:3-5

New Century Version

³ That appointed time is the fourteenth day of this month at twilight; they must obey all the rules about it.”

⁴ So Moses told the Israelites to celebrate the Passover, ⁵ and they did; it was in the Desert of Sinai at twilight on the fourteenth day of the first month. The Israelites did everything just as the Lord commanded Moses.