The prophet Ezekiel references the New Moons in several instances, initially in chapter 45.

vs. 17 . . . in the Feasts, and in the New Moons, and in the Sabbaths, in all solemnities of the house of Israel.

The New Moons are noted in the midst of the Feasts and Sabbaths as solemn times of observance.

The very next chapter further defines the importance and purpose of this time as recorded by this great prophet Ezekiel in chapter 46.

vs. 1 So says Adonay YHVH; The gate of the inner court that looks toward the east shall be shut the six working days; but on the Sabbath it shall be opened, and in the day of the New Moon it shall be opened.

The eastern gate was commanded by YHVH to remain shut except on Sabbath and New Moon, giving a special and similar significance to New Moon as to Sabbath.

vs. 3 Likewise the people of the land shall worship at the door of this gate before YHVH in the Sabbaths and in the New Moons."

The New Moons are a commanded time of worship along with the Sabbaths! Ezekiel 46:6 then follows with a notation as to the offerings to be given at New Moon.

The record of the prophet Ezekiel is that New Moon is a time to be solemnly gathered together for worship unto YHVH.