Numbers 28
To the sons of Israel, a day ended at twilight and seven twilights completed a week. The seventh day, from twilight on the sixth day to twilight on the seventh day was a special day of rest, to honor the Lord who created all things in six days and rested on the seventh day. A day was based on the setting of the sun but a month was based on moon cycles. A new month began with a new moon and twelve new moons meant a year. The first month of the year was special because on the fourteenth day of the first month, at twilight, a lamb was slain and eaten in remembrance of the Lord’s Passover. On the fifteenth day, the feast of unleavened bread began and was celebrated for seven days in remembrance of the exodus from Egypt. Based on these periods of times, the Lord commanded regular sacrifices: daily, sabbath, new moon (month), passover, and seventh day of unleavened bread. Every day was special and there were days considered most holy. Also seasons were celebrated but this was based on the harvest.
What should we take from this? The Lord God created all things. He created the day, the month and the seasons of the year. He should be given honor and thanksgiving in all things. The Lord created all things in six days, then he rested on the seventh day. The Lord died for our sins and was buried and rose again on the first day of the week. We, therefore, honor the Lord by coming together on the first day of the week and we annually remember the special first day, when he was the first to rise from the dead, the beginning of the resurrection; all will rise at his second coming.