Definitions of Biblical Days

The calendar day is the basic unit of time in the Bible. This unit breaks down into finer units of time, watches and hours, and those sub-day units of time become important in Passion Week.

Days are also combined to form larger units of time, called calendar time. Calendar time includes weeks, months, years, Sabbath and Jubilee year groups, as well as 10 fold jubilees and millenniums.

To accurately measure time, in all of its various aspects requires a precise definition of the base unit for all time, the calendar day.

In this article we develop a definition for the Bible’s Calendar day.


Most people have an instinctive definition of a day. Normal human days map closely to normal human waking hours. The day starts in the morning and runs until bedtime. This definition relates closely to the standard western idea for a day that starts at mid-night and runs through midnight the following night.

Westerners do not cross day-change times during waking hours so the instinctive definition works. This instinct is upset when travelers cross the international date line which is why such crossings are so interesting.

Unfortunately, various passages in the Bible show this definition is not what the Bible uses for its days.

Reference Location

The observed day varies continuously around the globe. Before the adoption of standard time zones the local time in each city was different and based on observation of the sun as it passed overhead.

Continuously varying time was acceptable when there was not much travel or other real-time communications between towns. People did not care that towns in other places where observing the sun, and thus the day, at different times.

With the invention of Railroads, and the need to keep trains from colliding based on accurate schedules and time-keeping, the world adopted a system of standard time zones where the number of possible times was theoretically reduced to 24 different hours.

In practice, political processes being what they are, different countries have different rules for their respective local times, yielding approximately 500 different actual local time zones around the earth today, roughly 20 times theoretical. (As an exercise, find the time-zone setting function in your computer and see how many choices it presents, my Linux system provides 26 different local time zone choices for the United States alone.)

Since the calendar day is a function of the time of day, the first question to be answered for defining a Bible day is a question of location. Where should the observer be located who establishes a Biblical day?

Establishing Jerusalem

Most of the events recorded in the Bible took place in or near what today is the modern nation of Israel. The most important city within that territory is Jerusalem, having been established as the capital and base for most of the key Bible stories since the time of King David.

Even the most remote stories in the Bible, that have location recorded, are recorded to have happened not more than 1/24th of the way around the world from Jerusalem. So it would seem that the natural answer would be to use the clock at Jerusalem in order to establish the day and thus the calendar.

This is satisfying for other reasons. Jerusalem is the city where God established his name the place of his dwelling. It was the place where his presence was located after Solomon finished the temple, and since we’re looking for a fixed place to measure time, there is no better candidate.


The Passover holiday is the best place to establish the day-break pattern. Passover, as a calendar date, was the 14th day of the 1st month. The Passover observance was a specially prepared meal. The following day, the 15th day of the 1st month, was a special Sabbath day when no regular work was to be done.

The Passover date itself was not a day off, not a Sabbath, and was to be the day when the Passover lamb was sacrificed and then prepared for eating at Sunset. The rest of the meal preparations also took place on the 14th day of the 1st month. Like any big holiday meal even today, the preparations were planned in the schedule and had time for them to complete. That work effort is difficult enough that no Sabbath was observed for the preparation, it was simply preparation day, a day of work for preparing a huge meal.

The next day, the 15th of the month, was a special Sabbath, a day of rest. This pattern helps establish that sunset or roughly the time of the evening meal is the time of the calendar break between the days. In the case of Passover, the meal itself marks the day-break, and once the meal is eaten, and everyone has had their fill, the Sabbath has started and it is now day 15 of the 1st month.

Symbolically, the meal marks the day-break because the Exodus from Egypt, which this meal is commemorating, was also a break-in-time. The children of Jacob left Egypt on this same day, and had been slaves before, and would be free after their departure. As will be shown, the Exodus was on a 10 fold Jubilee break, a major break in historical time.

Mosaic Covenant Day Break Time

Many times in the Mosaic Covenant people become unclean and remain this way until evening. This expression happens around such things as touching the carcass of a dead animal,(Lev 11:24) bodily emissions (Lev 14:5) sexual relations(Lev 14:18) or eating anything found dead or torn by wild animals.(Lev 17:15)

The idea of being unclean until evening is capturing an idea that the person involved is unclean through the end of the day.

We are also told, specifically, that the uncleanness continues until the sun goes down,(Lev 22:6-7) and not until someone sleeps for the night. This is important, uncleanness ends on a clock-event, not on a sleeping event.

This is interesting because it too suggests that the day ends at sunset.

God’s Day Breaks

Perhaps the most often quoted attempt at this is the days of creation given in Genesis.

5God called the light "day," and the darkness he called "night." And there was evening, and there was morning -- the first day. (Genesis 1:5 NIV)

The challenge of this is the expression at the end, like "evening and morning, day 1." The day number is at the end of each day, counting off the days, but the evening and morning terms may be counting off the remainder of the day after the creating part is finished, (suggesting a sunrise day break) or it may be indicating, more consistently with other scripture, that there was no creating going on at night, or that there is no night with God.

Because this creation story reduces to a difficult Hebrew grammar problem it is best to solve the day-break problem using longer narratives that dictate or otherwise imply the day-break time. To do that, we’re left with a search in other parts of scripture in order to establish the day-break time of day.

But, it should be noted that it is possible to read the Creation week story in such a way as to suggest that God’s day breaks are at sunrise, and not sunset.

No Night For God

To complicate matters the Bible also says God does not sleep, nor does he slumber.(Pss 121:4) In effect his days run day followed by day without night. So evening and morning are the same for God as there is no time in between. This is confirmed by the literary structure of Genesis chapter 1 where each day is separated by evening and morning, without anything happening in between.

Non-24 Hour Days

At 2 times in Bible history there were day lengths recorded as not 24 hours in length. This happened when Joshua was leading the children of Jacob as they conquered Canaan,(Num 10:12-13) it also happened under King Hezekiah.(2 Kgs 20:9-12)

These odd day-lengths introduce error, but no Bible text explains what corrections should be taken to eliminate the error. This implies that no corrections are needed.

Stated differently: We assume that any day-counts that span these odd-length days are already stated with the odd-lengths accounted for. Since neither odd-length day was longer than 1 day, the normal tolerance rules also cover this case.

Pole Shifts

Since originally writing this article I came to understand that these 2 days with odd lengths had no effect on the calendar. This is why there is no correction instructions given in scripture. The reason is these events conserved the earth’s angular momentum and were what we today would term Pole Shifts.[1]

Joshua’s Pole Shift moved the North Pole from Alaska to Hudson’s Bay. This probably changed the climate in ancient Canaan to a well watered garden capable of supporting the children of Jacob as they moved in.

Hezekiah’s pole shift moved the North Pole to its current location, warming Europe and North America for a second migration of the children of Jacob beginning at the time of the Assyrian Departure. The climate in Canaan shifted into what we see today, a semi-arid land no longer particularly well watered.

In pole shifts the angular momentum of the planet does not change. It is that momentum that drives the 24 hour day, so the 24 hour day does not change. What DOES change is that there are places with long days, as recorded in Joshua and Hezekiah’s times, and there are places with short days generally on the opposite side of the earth. These 2 different day lengths cancel, on average, with no compensation needed for a planet wide calendar. Only local time of day is messed up in a Pole Shift.

Pole shifts, especially Joshua’s Pole Shift may cause the time-of-day for prophetic fulfillment to have changed and thus be different from the current sunset related time. One possible example of this is Jacob moving the stone away from the well in order to water Laban’s daughter’s flocks. This event is near noon,(Gen 29:7) and is a prophetic map to Jesus’ tomb also being opened, but across the 2 pole shifts and in Jesus’ case it happens at night. The strange Creation Week time references may be the way they are because they are pre-pole-shift in nature.

Closing Thoughts

We will return to the question of time-of-day, but only after the time line is well established, and it will turn out that no matter what venue a prophetic headline is fulfilling in, no matter where in the world, the time of day if given prophetically will be measured in Jerusalem.

Even then, only certain times of day matter most of the time, and that time is sunset in Jerusalem.

This is why prophetic events like 911 happened in the morning on the East Coast of the United States. They were prophetic events that were on the tail end of long day counts and day counts end at the end of the calendar day, at sunset, in Jerusalem. Sunset in Jerusalem is in the morning hours after sunrise on the US East coast.


So, when do Bible days change?

Sunset is the best time from Scripture for when days change. For establishing the full calendar, clocks, or any other prophetic purpose related to time, a clock based on observed time, which then drives a sunset-day-break calendar is the correct strategy.