How to Calculate Dates from Datumn 598 BC Tishri and 597 BC Nisan

Verses	Ezekiel’s Dates	Tishri Datum, 598 BC	Nisan Datum, 597 BC	Approx. Modern Month	Event
Ezek 1:2	5th year, 4th mth, 5th-(12th) day	593	593	June /July	“7-day” Vision +390+40 *=430 days*
Ezek 8:1	6th year, 6th mth, 5th day	592	592	August /Sept.	First Temple vision
Ezek 20:1	7th year, 5th mth, 10th day	591	591	July /August	God refuses elders
Ezek 24:1	9th year, 10th mth, 10th day	590	589	December	Siege of Jerusalem begins
Ezek 26:1	11th year, ? mth, 1st day	588 or 587	587	Unknown	Judgment on Tyre
Ezek 29:1	10th year, 10th mth, 12th day	589	588	December	Prophecy against Egypt
Ezek 29:17	27th year, 1st mth, 1st day	571	571	March /April	Further Egypt prophecy
Ezek 30:20	11th year, 1st mth, 7th day	587	587	March /April	Egypt prophecy continued
Ezek 31:1	11th year, 3rd mth, 1st day	587	587	May /June	Egypt prophecy continued
Ezek 32:1	12th year, 12th mth, 1st day	587	586	February /March	Egypt prophecy continued
Ezek 32:17	12th year, ? Mth, 15th day	587 or 586	586	Unknown	Lament for Egypt
Ezek 33:21	12th year, 10th mth, 5th day	587	586	December	1st Refugee Post-Fall
Ezek 40:1	25th year, 1st mth, 10th day	573	573	March /April	Future Temple vision

Note: The approximate modern months are based on the Hebrew calendar’s alignment with the Gregorian calendar, which can vary slightly from year to year. The events are condensed descriptions based on the timeline provided.

Calculating Dates in Ezekiel: Harmonizing Nisan and Tishri Year-Counting Systems

Two datums are used:
- Nisan 1st, 597 BC (spring to spring)
- Tishri 1st, 598 BC (autumn to autumn)
Month counting:
- Months are counted from spring (Nisan), regardless of which datum is used– only the year may differ.
- Special Tishri calculation:
  - Subtract full years from 598 BC as usual.
  - For the partial year:
    - If the event is in months 1-6, add six months after autumn, then count months 1-6 as normal from spring.
    - If the event is in months 7-12, subtract six months before autumn, then count to months 7-12 normally from the previous spring.
Year alignment:
- Events in months 1-6 will be in the same year for both datums.
- Events in months 7-12 will be one year earlier in the Tishri datum compared to the Nisan datum.

Examples:

“5th year, 4th month, 5th day” translates to:
- Nisan datum: 593 BC (597 – 4 = 593)
- Tishri datum: 593 BC (598 – 5 = 593) Explanation: In Tishri counting, the 5th year spans from Tishri 594 BC to Tishri 593 BC. The 4th month falls in the latter half of this year (after months 7-12), so it’s in 593 BC.
“Ezek 24:1 | 9th year, 10th month, 10th day” translates to:
- Nisan datum: 589 BC (December) (597 – 8 = 589)
- Tishri datum: 590 BC (December) (598 – 8 = 590) Explanation: In Tishri counting, the 9th year spans from Tishri 590 BC to Tishri 589 BC. The 10th month falls in the first half of this year (within months 7-12), so it’s in 590 BC.