Does the Bible teach that the Sabbath begins and ends with sunset?

The Bible does not directly state that the Sabbath begins and ends at sunset. We derive this understanding from observing how the ancient Israelites reckoned the point at which one-day ends and the next day begins.

One problem we run into is the fact that the Hebrew words translated as "day" frequently refer to some period other than the twenty-four-hour day. Examples include "day of the Lord," "day of vengeance," and "in that day." A "day" is often the period between sunrise and sunset, which was the ordinary work day—the hours of daylight as opposed to the hours of darkness.

The ordinary work day ended at around sunset. But that leaves us with a question regarding the weekday: Does the weekday also end with sunset? If so, then sunset ends one weekday and begins a new weekday. On the other hand, if the weekday (like the work day) begins at sunrise, then sunrise is the point at which one weekday ends and a new weekday begins.

So which is it? Is there any scriptural evidence for one or the other?

Indeed, there is. Notice that the first day of the Feast of Unleavened Bread is "on the fifteenth day of the [first] month" (Leviticus 23:6). The first and last days of this seven-day feast were high days (verses 7–8).

The first day of this feast is the fifteenth, but notice when the fifteenth begins:

"In the first month, on the fourteenth day of the month at evening, you shall eat unleavened bread, until the twenty-first day of the month at evening" (Exodus 12:18).

Notice that the first day of the Feast of Unleavened Bread, which is the fifteenth day of the first month, begins "on the fourteenth day of the month at evening." This clearly means that the fifteenth day begins when the fourteenth-day ends! Here we see evidence of a "sunset to sunset" reckoning of days.

But that's not all. Notice that the last day of this seven-day feast ends not at sunrise but at sunset on the seventh day:

"…you shall eat unleavened bread, until the twenty-first day of the month at evening. For seven days no leaven shall be found in your houses, since whoever eats what is leavened, that same person shall be cut off from the congregation of Israel, whether he is a stranger or a native of the land (verse 18b–19).

The seventh day of the feast does not end with sunrise, but with sunset ("at evening") on the "twenty-first day of the month." As soon as the twenty-first day (or seventh day of the feast) ends, the twenty-second day of the month begins. Here, again, is proof that the Hebrews used a "sunset to sunset" reckoning for days of the week and month.

Finally, the Day of Atonement seals it.

"And the Lord spoke to Moses, saying: 'Also the tenth day of this seventh month shall be the Day of Atonement…. And you shall do no work on that same day, for it is the Day of Atonement…. It shall be to you a sabbath of solemn rest, and you shall afflict your souls; on the ninth day of the month at evening, from evening to evening, you shall celebrate your sabbath'" (Leviticus 23:26–28, 32).

The Day of Atonement, which is here said to be on the "tenth day of this seventh month," begins "on the ninth day of the month at evening" and is observed, "from evening to evening." This means that the tenth day of the month begins at the same "evening" the ninth day of the month ends. The Day of Atonement—the tenth day of the month—is observed: "from evening to evening."

Since Scripture shows plainly that three annual Sabbaths—the first and last days of the Feast of Unleavened Bread and the Day of Atonement—are observed according to the sunset-to-sunset reckoning, we have a strong biblical precedent for a sunset-to-sunset reckoning for all Sabbaths, both annual and weekly.