The Biblical Year

In this study we will see that the Biblical year has 360 days, having 12 months of 30 days each.

First published on the 29th of March 2013 — Last updated on the 25th of August 2021

A Biblical year has 360 days in Genesis and Revelation

In this study, we will see that the Biblical year has 360 days (having 12 months of 30 days each).

We think of a year as having 365.24 days. But, was it always like this? Many other nations and cultures have used different calendars from the one we commonly use. The Jews use a lunar calendar, with an extra month slipped in every few years to sort things out again (much like we do with leap years). The Muslims are using a lunar calendar dating from an event in the life of Mohammed. Take a look at the history of our modern calendar.
Many changes were still made to the calendar as late as the 16th century AD. The Bible was written long before that. We thus ask the question, "Does the Bible use the same calendar as we do?" The logical answer is, "It is likely that the Biblical calendar is not the same as our current calendar".

The days of Noah

In Genesis Chapters 7 and 8 we read,

Genesis 7:11 In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened.
12 And the rain was upon the earth forty days and forty nights.
24 And the waters prevailed upon the earth an hundred and fifty days.
Genesis 8:3 And the waters returned from off the earth continually: and after the end of the hundred and fifty days the waters were abated.
4 And the ark rested in the seventh month, on the seventeenth day of the month, upon the mountains of Ararat.

The time period from the 17th day of the 2nd month, to the 17th day of the 7th month (a period of exactly 5 months), is 150 days. This implies that a biblical month has 30 days, and a Biblical year has 360 days.

(Please note that the Biblical calendar is not the same as our calendar. Even though it looks like this must be the 17th of February to the 17th of July (which also happens to be 150 days), the Biblical year starts somewhere in our month of March (at barley harvest time) when the Jewish year starts.)

But, read carefully, it is the "600th year of Noah's life" which is dated from his unknown birthday. So we have absolutely no idea what month the starting day is.

The calendar in Revelation

The prophetic calendar in the Bible works in the same way.

Revelation 11:1 And there was given me a reed like unto a rod: and the angel stood, saying, Rise, and measure the temple of God, and the altar, and them that worship therein.
2 But the court which is without the temple leave out, and measure it not; for it is given unto the Gentiles: and the holy city shall they tread under foot forty and two months.
3 And I will give power unto my two witnesses, and they shall prophesy a thousand two hundred and threescore days, ...
6 These have power to shut heaven, that it rain not in the days of their prophecy: and have power over waters to turn them to blood, and to smite the earth with all plagues...

Forty and two months is 1260 days. This once again implies that each month is 30 days, and a year is 360 days. God is always the same.

MALACHI 3:6   For I am the LORD, I change not;

(To get a clue who one of these prophets is, see James 5:17. "Elias (Elijah) was a man subject to like passions as we are, and he prayed earnestly that it might not rain: and it rained not on the earth by the space of three years and six months."
3½ years is the same as 42 months, is the same as 1260 days.)

Scriptural basis

The fact is that we cannot use a Gentile calendar. In Isaiah we read that everything has to be according to the law and the testimony (the Word of God).

Isaiah 8:19 And when they shall say unto you, Seek unto them that have familiar spirits, and unto wizards that peep, and that mutter: should not a people seek unto their God? for the living to the dead?
20 To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.

We are therefore living very dangerously if we use anything that is not Scriptural to explain the Scriptures. Even to the point of being associated with wizards and the occult!

Our calendar

There is another reason we cannot use Gentile years for Biblical prophecies. Julius Caesar only got the Gentile calendar correctly lined up in "the year of confusion" (45 BC), when he added 90 days to realign the calendar with the earth’s seasons. After that Augustus Caesar made a change involving a few days.
Pope Gregory 13th finalized the current calendar in AD 1582. He did this by adjusting the leap years at the beginning of each century. Ten days were removed from the month and October 4 was followed by October 15. All these changes make it almost impossible for anybody to determine exactly (i.e. to the day) any of the dates used in some prophecies. We can however safely and accurately work with the nearest part of a year.

The Beast

Daniel 7:23 Thus he said, The fourth beast shall be the fourth kingdom upon earth, which shall be diverse from all kingdoms, and shall devour the whole earth, and shall tread it down, and break it in pieces.
24 And the ten horns out of this kingdom are ten kings that shall arise: and another shall rise after them; and he shall be diverse from the first, and he shall subdue three kings.
25 And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.

Looking at who has changed the times (calendar), we can now also identify the fourth beast! The pagan Romans of Julius Caesar's day, and more lately, the Roman Catholic Church.

Pagan Rome and the Roman Catholic Church sound like two very different systems. But when the barbarian tribes destroyed the pagan Roman Empire, then that antichrist pagan Roman spirit resurrected back to life on the ruins of the Roman Empire as the Roman Catholic Church. Same spirit, same beast.

Must we rely on "the beast" to produce us a calendar before we can work Bible prophecies out? Certainly not!


Converting a certain number of biblical years to our year-unit would imply multiplying by 360 and dividing by 365.24219879 (the length of our current solar calendar year).

Basically, it means that 69 of our Gentile Roman years are equal to 70 Bible years.

So, 70 weeks = 70 x 7 = 490 days.

490 Bible years = 490/70 = 7 years less for our Gentile Roman calendar.

Thus, 490 Bible years = 490 - 7 = 483 years on our calendar.

GENESIS 29:27   Fulfil her week, and we will give thee this also for the service which thou shalt serve with me yet seven other years.

A day can represent a year in prophecy.

“The grace of our Lord Jesus Christ be with you.” — 1 Corinthians 16:23