Nowruz نوروز
When is Chaharshanbe Suri? Working out the date each year
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Chaharshanbe Suri is the one date in the Nowruz season you cannot get by adding a fixed number of days to anything. Its distance from Nowruz changes every year, and the rule most sites give you is subtly wrong.
The rule, stated properly
Two things have to be right.
It is the last Wednesday of the Persian year — not the last Wednesday before Nowruz. Those sound identical and are not, because Nowruz itself can fall on a Wednesday.
It is the eve. The festivities begin at sunset the evening before, so the Gregorian date you want is the Tuesday. Both parts matter; drop either and you get a wrong date in some years.
The dates
| Persian year | Chaharshanbe Suri | Gregorian | Last Wednesday of the year | Nowruz after it | Gap |
|---|---|---|---|---|---|
| 1401 | 23 Esfand | Tue 14 Mar 2023 | Wed 15 Mar 2023 | Tue 21 Mar 2023 | 7 days |
| 1402 | 22 Esfand | Tue 12 Mar 2024 | Wed 13 Mar 2024 | Wed 20 Mar 2024 | 8 days |
| 1403 | 28 Esfand | Tue 18 Mar 2025 | Wed 19 Mar 2025 | Fri 21 Mar 2025 | 3 days |
| 1404 | 26 Esfand | Tue 17 Mar 2026 | Wed 18 Mar 2026 | Sat 21 Mar 2026 | 4 days |
| 1405 | 25 Esfand | Tue 16 Mar 2027 | Wed 17 Mar 2027 | Sun 21 Mar 2027 | 5 days |
| 1406 | 24 Esfand | Tue 14 Mar 2028 | Wed 15 Mar 2028 | Mon 20 Mar 2028 | 6 days |
Look at the last column. The gap to Nowruz runs 7, 8, 3, 4, 5, 6 days across six consecutive years. There is no offset to memorise.
Where the popular rule breaks
“The last Tuesday before Nowruz” is repeated widely. Test it on Persian year 1402.
Nowruz 1403 fell on Wednesday 20 March 2024. The last Tuesday before that date is 19 March 2024. But the last Wednesday of the Persian year 1402 was 13 March, so Chaharshanbe Suri was the evening of Tuesday 12 March 2024.
The naive rule is wrong by a full week.
It fails precisely when Nowruz lands on a Wednesday, because then the “last Wednesday before Nowruz” and “the last Wednesday of the year” are different Wednesdays. That happens irregularly, so a rule that looks reliable for years in a row breaks without warning.
Why the gap moves at all
Because Nowruz is not fixed to a weekday or a Gregorian date. It is set by the spring equinox relative to noon in Tehran: if the equinox falls before noon Tehran time, that day is 1 Farvardin; if after, the next day is.
| Year | Equinox (UTC) | In Tehran (UTC+3:30) | Before noon? | Nowruz | Weekday |
|---|---|---|---|---|---|
| 2024 | 20 Mar 03:07 | 20 Mar 06:37 | yes | 20 Mar 2024 | Wednesday |
| 2025 | 20 Mar 09:01 | 20 Mar 12:31 | no, by 31 min | 21 Mar 2025 | Friday |
| 2026 | 20 Mar 14:46 | 20 Mar 18:16 | no | 21 Mar 2026 | Saturday |
| 2027 | 20 Mar 20:25 | 20 Mar 23:55 | no | 21 Mar 2027 | Sunday |
| 2028 | 20 Mar 02:17 | 20 Mar 05:47 | yes | 20 Mar 2028 | Monday |
2025 is the striking one: the equinox missed noon Tehran by 31 minutes, which pushed Nowruz to 21 March. Half an hour decided the date of the new year — and with it, how far Chaharshanbe Suri sat from it.
Because Nowruz drifts across weekdays like this, the last Wednesday of the Persian year lands anywhere from the 23rd to the 29th of Esfand. The drift is covered in Nowruz and the Gregorian drift, and the noon-Tehran rule in why the Persian year starts at the equinox.
Working it out yourself
Two steps, no astronomy needed:
- Find the last day of Esfand in the Persian year — 29 days, or 30 in a leap year.
- Walk back to the nearest Wednesday. Chaharshanbe Suri is the evening before that Wednesday.
You can do step 1 with the converter and step 2 on a calendar. If the Persian year is a leap year, Esfand has a 30th day, which shifts the whole calculation — see 30 Esfand explained.
Frequently asked questions
When is Chaharshanbe Suri 2026?
The evening of Tuesday 17 March 2026, which is 26 Esfand 1404. It is the eve of the last Wednesday of that Persian year, 18 March 2026.
Why is a festival named after Wednesday celebrated on a Tuesday?
Because it is the eve. The bonfires are lit after sunset on the Tuesday, running into the last Wednesday of the Persian year, so the Gregorian date people mark is the Tuesday.
Is Chaharshanbe Suri always the last Tuesday before Nowruz?
No, and that shortcut fails when Nowruz falls on a Wednesday. In Persian year 1402 it gives 19 March 2024, while the correct date was 12 March 2024 — a week out.
How many days before Nowruz is Chaharshanbe Suri?
It varies. Across Persian years 1401 to 1406 the gap runs 7, 8, 3, 4, 5 and 6 days, because Nowruz moves relative to the weekday while the festival is pinned to a Wednesday.
What date is it in the Persian calendar?
It falls in the last week of Esfand. Across Persian years 1401 to 1406 the eve lands on the 22nd, 23rd, 24th, 25th, 26th and 28th, depending on the weekday and whether Esfand has 29 or 30 days.