According to Exodus 20, which day was set apart as the Sabbath?

According to Exodus 20, the seventh day was set apart as the Sabbath.

The fourth commandment tells Israel to remember the Sabbath and keep it holy. It prohibits ordinary work by the Israelites, their children, servants, livestock, and resident foreigners within their settlements. The command links the pattern to six days of creation followed by rest on the seventh day.

Exodus 20 is the version of the commandment in the Ten Commandments. A related Sabbath rule appears earlier in Exodus 16, where the people gather manna for six days and rest on the seventh. The weekly rhythm therefore appears before the commandments are formally presented at Sinai.

The Sabbath should not be confused with annual festivals such as Passover. Passover has a calendar date and a festival period, while the Sabbath is a recurring seventh-day observance.