And it came to pass on the day that Moses had fully set up the tabernacle, and had anointed it, and sanctified it, and all the instruments thereof, both the altar and all the vessels thereof, and had anointed them, and sanctified them; (Numbers 7:1)
According to Ex. 40:17, 18, This would be the first day of the first month of the second year of wandering. It is the day of the completion of the tabernacle and the anointing of the altar (see vs. 1, 10, 84, 88). The narrative now returns to the first day of the second year, the month preceding the numbering of the armies.