2 Kings 4:23
He said, "Why would you want go to him today? It is neither new moon nor Sabbath." She said, "It's alright."
Numbers 10:10
"Also in the day of your gladness, and in your set feasts, and in the beginnings of your months, you shall blow the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; and they shall be to you for a memorial before your God. I am Yahweh your God."
Numbers 28:11
"'In the beginnings of your months you shall offer a burnt offering to Yahweh: two young bulls, and one ram, seven male lambs a year old without blemish;
1 Chronicles 23:31
and to offer all burnt offerings to Yahweh, on the Sabbaths, on the new moons, and on the set feasts, in number according to the ordinance concerning them, continually before Yahweh;
Isaiah 1:13-15
Bring no more vain offerings. Incense is an abomination to me; new moons, Sabbaths, and convocations: I can't bear with evil assemblies.