Ezekiel 46:1  Thus saith Yahweh; The gate of the inner court that looketh 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.
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 Yahweh.

As seen below From the last shabat until the day of the new moon is a special time of rejoicing, beginning with the fourth quarter shabat, (fourth sabbath) and lasting until the new moon day, when we, if saved, shall eat of the Tree of Life yielding it's new fruit each new moon.

Luke 6:1 And it came to pass on the second Sabbath after the first, that He went through the corn fields; and His disciples plucked the ears of corn, and did eat, rubbing them in their hands.

   Looking down from above the solar plane, the earth and moon orbit the sun. Tracking orbital motion, the point tip is the moon, almost still in relative space. Moon is at transitional point as the earth travels past, the moon is pulled from the suns gravity, which had accelerated its speed, as it had traveled toward the sun. Breaking away from the sun's pull, the moon begins to travel from the sun, accelerating on to orbit the earth again. As it begins moving in relative space, in a new direction, away from the sun, the new moon shows a sliver of light.
See Patriarchs and Prophets page 654 & 655 Day of the
New Moon follows the last sabbath, or extra day 30th: The 30th day, or new moon day, is not one of the week days.
Day of the
New Moon is the "wine bottle" - 24 hour period, that conjunction "bursts open" as the birth day of a newborn child
This is to illustrate that the "extra day" creates a three day shabat-lunar event - see 29th below as this is a 7th day shabat 29 30
From one shabat and new moon to another shall all flesh come together to worship our Creator
Day of the new moon
1
 
1st day 2nd day 3rd day 4th day 5th day 6th day 7th day
Sabbath
2 3 4 5 6 7 8
Sabbath
9 10 11 12 13 14 15
Sabbath
16 17 18 19 20 21 22
Sabbath
23 24 25 26 27 28 29
The 29th 30th and 1st (new moon) make a 3 day event with Yah our Creator.
On  29 day moons, the 29th day, 7th day Sabbath, is followed by the New Moon.