The actual month (not cathoik/modern science) starts with new moon. In fact word for new moon and 1st of month is the same: chodesh (strong's #2320 https://biblehub.com/hebrew/2320.htm Enemy does not want you to know, celebrate, obey any Biblical holidays, including "churches" and vast majority of religious groups . Because knowing, observing them is of great importance. People are expelled because they speak of Biblical Holidays, Biblical calendar.
New moon/1st of each month It is the day we celebrate, feast, ponder, study Word of YAHashua The Christ. There are few fragments in holy Bible that are preserved. However in Book of Jubilees (which I understand was taken out of Holy Bible/Books related to Holy Bible along with Book of Enoch, Books of Maccabees, Book of Jasher, Book of Ezdra, Baruch {I gave links to pdf of them} in fact that politic of taking books/verses continues to this day).
Here is prayer Abram (before he was given name Abraham) prayed on new moon, amazing Word of Elohim (God)
"And in the sixth week, in the fifth year thereof, Abram sat up throughout the night on the new month of the seventh month to observe the stars from the evening to the morning, in order to see what would be the character of the year with regard to the rains, and he was alone as he sat and observed.
And a word came into his heart and he said: All the signs of the stars, and the signs of the moon and of the sun are all in the hand of YAHWEH. Why do I search them out?
If He desires, He causes it to rain, morning and evening; And if He desires, He withholds it, And all things are in his hand.'
And he prayed that night and said, 'My Sovereign Ruler, YAHWEH Most High, You alone are my Sovereign Ruler, And You and Your dominion have I chosen. And You have created all things, And all things that are the work of Your hands.
Deliver me from the hands of evil spirits who have dominion over the thoughts of men's hearts, and let them not lead me astray from You, my Sovereign Ruler. And establish You me and my seed forever that we go not astray from henceforth and forevermore.'
And he said, 'Shall I return unto Ur of the Chaldees who seek my face that I may return to them, am I to remain here in this place? The right path before You prosper it in the hands of Your servant that he may fulfill it and that I may not walk in the deceitfulness of my heart, O YAHWEH my Sovereign Ruler.' And he made an end of speaking and praying, and behold the word of YAHWEH was sent to him through me, saying: 'Get you up from your country, and from your kindred and from the house of your father unto a land which I will show you, and I shall make you a great and numerous nation.
And I will bless you And I will make your name great, And you shall be blessed in the earth, And in You shall all families of the earth be blessed, And I will bless them that bless you, And curse them that curse you.
24 And I will be a Sovereign Ruler to you and your son, and to your son's son, and to all your seed: fear not, from henceforth and unto all generations of the earth I am YAHWEH your Sovereign Ruler.'
And YAHWEH ALMIGHTY said: 'Open his mouth and his ears, that he may hear and speak with his mouth, with the language which has been revealed'; for it had ceased from the mouths of all the children of men from the day of the overthrow (of Babel).
And I opened his mouth, and his ears and his lips, and I began to speak with him in Hebrew in the tongue of creation." Jubilees 12:16-26