Appointed Times for Worship [Leviticus 23]
1 The LORD spoke to Moses: 2 "Speak to the Israelites and tell them: These are My appointed times, the times of the LORD that you will proclaim as sacred assemblies.
3 "For six days work may be done, but on the seventh day there must be a Sabbath of complete rest, a sacred assembly. You are not to do any work; it is a Sabbath to the LORD wherever you live.
4 "These are the LORD's appointed times, the sacred assemblies you are to proclaim at their appointed times. 5 The Passover to the LORD comes in the first month, at twilight on the fourteenth day of the month. 6 The Festival of Unleavened Bread to the LORD is on the fifteenth day of the same month. For seven days you must eat unleavened bread. 7 On the first day you are to hold a sacred assembly; you are not to do any daily work. 8 You are to present a fire offering to the LORD for seven days. On the seventh day there will be a sacred assembly; you must not do any daily work."
God not only instituted a once a week time for worship but He also appointed different times throughout the year to stop work and worship Him.