The New Moon is celebrated on the first day of every month.
Numbers 10:10 Also in the day of your gladness, and in your solemn days, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; that they may be to you for a memorial before your God: I am the Lord your God.
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;
Isaiah 66:23 And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the Lord.
Ecclesiasticus 43:6-8 He made the moon also to serve in her season for a declaration of times, and a sign of the world.7From the moon is the sign of feasts, a light that decreaseth in her perfection.8The month is called after her name, increasing wonderfully in her changing, being an instrument of the armies above, shining in the firmament of heaven;