The New Moon determines the beginning of a month according to the Bible,
Psalms 81:3 &; Blow up the trumpet in the new moon, in the time appointed,
on our solemn feast day”.Vs 4- For this was a statute for Israel, and a law of
the God of Jacob.

Psalms 104:19 , "He appointed the moon for seasons:". When the dark side
of the moon is facing toward the earth the New Moon has begun. The New
Moon for the children of Israel is to be observed as a High Holy day/Sabbath
day- On the New Moon the Israelites are allowed to Feast/cook. As long as
the New Moon does not fall on the Lords weekly Sabbath day.

Numbers 10:10 – “Also in the day of your gladness, and in your solemn days,
and in the beginning of your months. Ye shall blow with the trumpets over
your peace offerings; that they may be to you for a memorial before your God:
I am the LORD your God. The feast is intended to be kept with a joyful spirit.
Today we honor the New Moon in the faith of Christ- because he the Children
of Israel’s ultimate sacrifice.

Isaiah 66:23, "And it shall come to pass, that from one new moon to another,
shall all flesh come to worship before me". This scripture demonstrates that
the New Moon will be kept in the Kingdom as well. This will be a law and
standard to keep in the Lords Kingdom.

Judges 5:11 “They that are delivered from the noise of archers in the places
of drawing water, there shall they rehearse the righteous acts of the LORD….”

 

Ecclesiasticus 43:6 "He made the moon also to serve in her season for a

Verse 7, From the moon is the sign of feasts, a light that decreaseth in her perfection. 
Verse 8, The month is called after her name,( The NEW MOON) increasing
wonderfully( Meaning going from dark to light /when the dark side of the moon is
towards the earth it’s called the New Moon) in her changing, being an instrument
of the armies above, shining in the firmament of heaven; Verse 9 , The beauty of

heaven, the glory of the stars, an ornament giving light in the highest places of the
Lord."