Gen 2: 1Thus the heavens and the earth were finished, and all the host of them. 2And on the seventh day God finished his work that he had done, and he rested on the seventh day from all his work that he had done. 3So God blessed the seventh day and made it holy, because on it God rested from all his work that he had done in creation.
In the beginning God created heaven and earth. It took Him six days. Each of these days is recorded as having a beginning and ending. The seventh day, when God ceased creating, and rested from the work of creation. It had no beginning or end. The day was holy, but it hasn’t ended yet.
The ancient people measured their time by the sun, moon and stars. Historical records show that they measured the phases of the moon, and recorded sunrises and sunsets. They knew about equinoxes and solstices and eclipses. Their base times were days, nights, and months. Not weeks. They are a more modern way of measuring time.
The Israelites started each month with the new moon, and it was a day of sacrifice to the Lord. Numbers 28: 11“At the beginnings of your months, you shall offer a burnt offering to the LORD: two bulls from the herd, one ram, seven male lambs a year old without blemish; 12also three tenths of an ephah of fine flour for a grain offering, mixed with oil, for each bull, and two tenths of fine flour for a grain offering, mixed with oil, for the one ram; 13and a tenth of fine flour mixed with oil as a grain offering for every lamb; for a burnt offering with a pleasing aroma, a food offering to the LORD. 14Their drink offerings shall be half a hin of wine for a bull, a third of a hin for a ram, and a quarter of a hin for a lamb. This is the burnt offering of each month throughout the months of the year. 15Also one male goat for a sin offering to the LORD; it shall be offered besides the regular burnt offering and its drink offering.
They are to stand every morning to thank and to praise the Lord, and likewise at evening, and to offer all burnt offerings to the Lord, on the sabbaths, the new moons and the fixed festivals in the number set by the ordinance concerning them, continually before the Lord.
After the new moon, the 8th, 15th,and 22nd days were sabbaths. The days in between sabbaths were sabbath 1, sabbath 2, etc till the day before sabbath,, which was preparation day.
Because the new moon happened at different times throughout the year, the sabbath likewise was at different times, though still 7 days after the new moon, or the previous sabbath. The month is approx. 29.5 days.
The sabbath was not a day of worship for the Israelites. It was a day of REST, a cessation of work. As God rested from His work of creation the first seventh day, so were the Israelites told to rest from their work. Their families, their animals, their servants, everyone (apart from the priests) rested. They were to remember that God rested, and at the same time they were to look forward to eternal rest from Christ, and eternal redemption, just as they had been redeemed from slavery in Egypt.
Christians were not given a day in which to rest. Christ was here, and He was their rest, He offered them rest for their souls. They did not need a sign post for what was already here. Here was eternal rest, eternal peace, eternal joy, all because of eternal love. God is love, and Jesus is both.
God rested on the seventh day. He gave the sabbath to the Israelites to point them to Jesus and rest, and to remember His rest, His cessation of creation. We, His followers, worship Him who gives us both eternal rest and eternal life.