Charles Ellicott Commentary Numbers 28:11

"And in the beginnings of your months ye shall offer a burnt-offering unto Jehovah: two young bullocks, and one ram, seven he-lambs a year old without blemish;" — Numbers 28:11 (ASV)

In the beginnings of your months ... — The beginning of the month was announced by the blowing of the silver trumpets (Numbers 10:10). Increased respect was paid to the beginning of the month in later times. Trade was suspended (Amos 8:5), and religious instruction appears to have been given at this time (2 Kings 4:23).