New Moon Sabbaths 

Isaiah 66:23And it shall come to pass That from one New Moon to another, And from one Sabbath to another, All flesh shall come to worship before Me,” says the Lord.

Our lunar Sabbaths occur during each Hebrew month, incrementally at intervals of seven days from the new moon. Hence, lunar Sabbaths fall on the 8th, 15th, 22nd and 29th days of each Hebrew month. (Instead, some lunar Sabbatarians observe the 7th, 14th, 21stand 28th days of each Hebrew month.)

The lunar month, designated in the Hebrew calendar from new moon to new moon, is 29.5 days long. Since a calendar cannot divide days in half, in practice, some Hebrew months last 29 days, others last 30 days. (Lunar Sabbatarians express divided convictions concerning the way the “extra” days are handled. Not all of them treat them in the same way.)

These extra day(s) in the lunar month mean that the lunar Sabbath falls on a different day of the week from lunar month to lunar month. The lunar Sabbath will fall on the same day of the week only four consecutive times before the end of the lunar month arrives and the lunar Sabbath is “reset” based on the next new moon.

For example, it may fall on a Thursday in one Hebrew month, but on a Sunday in another lunar month, since the lunar Sabbath is reset after the passage of 29 or 30 days, that is, reset with the coming of another new moon.