Please remember that the seven-day weekly cycle was established by God at Creation based upon the rotation of the earth, bringing to every location on the earth a sunset (translated "evening") and a sunrise (translated "morning") to divide the day from the night. Day and night together made a 24-hour day, and each day was counted from sunset to sunset.
God completed His work of creation at the end of six days and rested on the seventh day. God sanctified the seventh day of the week as a Sabbath of rest. On today's calendars the Sabbath day is Saturday.
Concerning the lunar Sabbath teaching, it is a figment of the imagination of men who think they know more than God and invent a calendar that breaks the weekly cycle that God established at creation. Their lunar Sabbath calendar begins the weekly cycle with the new moon of each month, which places the Sabbath on different week days, rather than the seventh day of the week. According to this teaching, each month is composed of four seven-day periods, and any remaining days in the month are not counted. Consequently, their calendar loses from one to two days a month.
When the promoters of the lunar Sabbath calendar claim everybody is wrong except them, they are being utterly foolish. The Bible makes it very clear that they are the ones who are wrong.
Nowhere does the Bible say we are to keep the weekly Sabbath based on the new moon of each month. The Sabbath is based on the movement of the sun as the earth turns—not on the orbit of the moon as it circles the earth each month.
The lunar Sabbath calendar is the height of folly and shows the great arrogance of men who break God's command by replacing the weekly Sabbath with a seven-day cycle based on the new moon. The new moon sets the beginning of the month—not the beginning of the weekly cycle, which continues from one month to the next.
The Calculated Hebrew Calendar determines the beginning of the months in the year based on the seven-day weekly cycle. This upholds the Biblical command for observing the weekly Sabbath.
If you have rejected the Biblical teaching and have accepted the lunar Sabbath calendar, I hope you will heed what I have written and will repent. If you do not repent, you may find yourself in a worse position in your relationship with God than do Sunday-keepers. While Sunday-keepers worship on the wrong day, they do not make the spiritually fatal mistake of breaking God's seven-day weekly cycle.