Exodus 12:2

12:2 “This month is to be your beginning of months; it will be your first month of the year.

Exodus 40:2

40:2 “On the first day of the first month you are to set up the tabernacle, the tent of meeting.

Exodus 40:17

40:17 So the tabernacle was set up on the first day of the first month, in the second year.