Numbers 28:11

And in the beginnings of your months ye shall offer a burnt offering unto the LORD; two young bullocks, and one ram, seven lambs of the first year without spot;

In the beginnings of your months. These were held as sacred festivals; and though not possessing the character of solemn feasts, they were distinguished by the blowing of trumpets over the sacrifices (Numbers 10:10), by the suspension of all labour, except the domestic occupations of women (Amos 8:5), by the celebration of public worship (2 Kings 4:23), and by social or family feasts (1 Samuel 20:5). These observances are not prescribed in the law, though they obtained in the practice of a later time. The beginning of the month was known, not by astronomical calculations, but, according to Jewish writers, by the testimony of messengers appointed to watch the first viable appearance of the new moon, and then the fact was announced through the whole country by signal-fires kindled on the mountaintops. The new moon festivals having been common among the pagan, it is probable that an important design of their institution in Israel was to give the minds of that people a better direction; and assuming this to have been one of the objects contemplated, it will account 'for one of the kids being offered unto the Lord' (Numbers 28:15), not unto the moon, as the Egyptians and Syrians did. The Sabbath and the new moon are frequently mentioned together.