Many people come to different conclusions around the seventy year exile prophesied I. Jeremiah 25:11. Some say they were 360 day prophetic years, others say "seventy years" is a phrase to mean a generation.

The dates for the captivity vary, ranging from 606 BC to 536 BC. Wikipedia and others say the exile lasted from 605 BC to 537 BC. That's 68 years. However, with those dates I've realised that, although it only makes 68 solar years, it makes 70 lunar years.

I know the Hebrew calendar is lunar based, with a typical year consisting of twelve lunar months and having an additional 13th month once the first month drifted from Spring (when the first month is supposed to occur). These leap months are now mathematical, consistent, and predictable, but back in the time of ancient Israel these leap months were off the cuff, only occurring of the high priest said so at the end of the twelve months. Therefore I'm assuming there had to be some general idea of what a "year" actually was, time wise. Otherwise people will could make pledges for X years without any knowing of how many months they had pledged for.

So maybe when Jeremiah prophesied the 70 year exile, the Jews at the time could've understood that as being a time duration of 70 typical years, or 70x12 months.

Is this argument plausible? What are your opinions?

I've looked into the Talmud for answers and it appears that there is a difference between someone making a pledge for "a year" or "this year" and someone making a pledge for "one year". "This/a year" would mean for the rest of the year, even if that year turned into a leap year, whereas "one year" indicates 12 lunar months. I don't know how "seventy years" would be viewed as in the Talmud.

  • How "seventy years" would be viewed in the Talmud is more question for the Hebrew Stack exchange than this one. However, years ago, I was taught by a Priest that there are certain numbers in the Old and New testament which have "mystical" meanings, that is, they may mean what they actually are, but they may mean something else besides, and one of the numbers mentioned in this regard was "seventy". .
    – brasshat
    Jun 23, 2017 at 19:33
  • Cross-posted from Hermeneutics.SE, or vice-versa.
    – Lucian
    Aug 31, 2021 at 18:49

3 Answers 3


The Hebrew calendar is actually a luni-solar one (https://en.wikipedia.org/wiki/Hebrew_calendar).

It is based not only on the moon, but also by the sun. The reason is the moon revolves slower around the earth (about 29-30 days) than the earth around the sun (about 365.25 days). This means that roughly every three years, the Hebrew calendar "added" a month (called intercalary month) of 29-30 days to bring the lunar time back in line with the sun's time.

This lunar/solar necessity is spelled out clearly in Ex. 12:2 (This month shall be unto you the beginning of months: it shall be the first month of the year to you.) It is the beginning of months (plural). This, in combination with the barley first fruit wave sheaf offering (Lev. 23:10) and other seasonal feasts. If they merely followed the moon cycle, within a couple of years there would not be barley to wave, nor to harvest 50 days later at Pentecost (Lev. 23:15-22). So, they "added" the month to bring "agriculture time" back into the moon and sun alignment so they could follow the commandments.

This necessity and time keeping is also clearly found centuries later with Josephus in his Antiquities of the Jews Book 3 Chapter 10.5 ("5. In the month of Xanthicus, which is by us called Nisan, and is the beginning of our year, on the fourteenth day of the lunar month, when the sun is in Aries,"). The alignment time was thus marked as the spring equinox. This means they required the new moon and full moon to both be after the Spring Equinox. The sun would be in Aries and alight the new moon also in Aries.

So, the Seventy Years is in fact 70 years as measured by the rotation past the Spring Equinox and not by the lunar months (30 days or 360 days) alone.

  • I already mentioned the leap month system in my post. Nowadays it's part of the 19 year lunar cycle. 7 times out of 19 years a leap month is added to fit the solar cycle. However, back in the time of ancient Israel, the decision whether or not to add a leap month was purely based on observation. This was presumably done in the twelfth month. If it hadn't looked like spring was around for Nisan, the priest would declare a leap month. Thus, how long the calendar year was going to last was unpredictable, so it would make sense to generalise the meaning of a "year" to avoid uncertainty of time.
    – user329957
    Jun 23, 2017 at 23:59
  • Plus a "sheaf" of wheat can be stored. It's not the offerings which require Nisan to be in spring but simply because the name of the first month was originally called "abib" which means "green ears", indicating the time of Spring.
    – user329957
    Jun 24, 2017 at 0:03
  • Well, the "general idea" of a year would revolve about the Spring Equinox. Josephus defines it (sun (to define the new moon) and (full) moon in Aries, first constellation after Spring Equinox), which presumably would have been what had been followed historically.
    – SLM
    Jun 24, 2017 at 14:38

The prophecy of Jeremiah’s 70 years has two aspects, but unfortunately, commentators conflate them with each other. A few years after the Assyrian Empire collapsed, he made his extraordinary prediction that the incoming empire of Babylon would last seventy years then it too would end. His word came true to the very year! Babylon fell to the Medes and Persians in October 539 BC, seventy years after the demise of Assyria in 608 BC. (Nineveh was lost in 612 BC but Assyria's last stand was the city of Harran in 608 BC)

However, there is a ‘dual fulfilment’ aspect to this prophecy, one describing Babylon's duration (Jeremiah 25:8-14), and the other describing Jerusalem lying desolate for a concurrent 70 years. (2 Chronicles 36:1-21) Below is a diagram showing the date of Jeremiah’s prophecy and the two counts of 70 in fulfilment of his word:

Babylonian Captivity Timeline

The two predictions were offset from each other because Babylon's start was 608 BC, whereas the siege of Jerusalem started 17th December 589 BC. Then, the count of seventy pertaining to Jerusalem lasted until 18th December 520 BC when Haggai marked it as the end of Jerusalem's punishment. "The vine, the fig tree, the pomegranate, and the olive tree have yielded nothing, but from this day on I will bless you." (Haggai 2:19) This seventy year period is confirmed by Haggai’s contemporary a few months later in Zechariah 1:12.

A problem arises when we count the days between the dates given. From the siege until Haggai’s finish-point is 25202 days exactly. Divide that by 365.242 and it comes to a precise 69 years. So, what was the 70th year? There are three explanations offered, and anyone interested in this subject must choose between them.

  1. Jeremiahs prophecy of 70 years was approximate, and 69 years is close enough.
  2. The original Hebrew calendar included an extra ‘Jubilee year’ every 49 years, and one such Jubilee has to be calculated into this period.
  3. A different calendar of 360 days was used for prophetic calculations and 70 such years equals nearly 25202 days.

My personal view is number #2.

  • Thank you. Did the Babylonians control Israel and the surrounding countries after the fall of Haran, do you know? I thought it was only after the Babylonians defeated the Egyptians in the battle of Carchemish in 605 BC that Israel became a vassal kingdom under the Babylonians? Before then they were ruled by Egypt.
    – user329957
    Jun 25, 2017 at 16:44
  • Haran marks the last stand of the previous empire, Assyria. After its fall Babylon continued to expand as you describe. Jun 25, 2017 at 20:38
  • But Jeremiah said the nations would serve Babylon for seventy years and Judah was not under Babylon until 605 BC?
    – user329957
    Jun 25, 2017 at 21:51

I never could believe in a 360 day prophetic year. God would not use a length of year that did not apply to the years contained within the prophesy. I do believe that ancient years used to consist of 360 days. See an article on this subject at http://xwalk.ca/360vs365.html.

I also think of the 70 years a little different than most. I believe it has to do with the time Israel was without a Temple, Jeremiah 25:11, says the land will be a desolation and a horror. I believe that happened when the Temple was destroyed in 586 BC. In the Book of Haggai Chapter 1, even after some of the Israelites returned the land was unproductive until the Temple was completed in 516 BC (Ezra 6:15). Thus from 586 BC to 516 BC is 70 years.

  • Please quote the most important part(s) of the linked article in case the link no longer works in the future.
    – Null
    Nov 8, 2019 at 17:36
  • Indications are that early civilizations around the world used calendars with months of 30 days and years of 360 days. Also, during the time of the flood of Noah’s day a period of 150 days started on the 17th day of the 2nd month and ended on the 17th day of the 7th month (Gen. 7:11, 24 and 8:3-4). Probably indicating 30-day months for 5 months. Nov 9, 2019 at 21:34

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