Hijri date converter
Convert a Gregorian date to the Hijri calendar, or a Hijri date to the Gregorian one. Both directions are on this page as separate tools, so you can convert a date and convert the answer straight back.
Two calendars answer here, and each result says which one did. From 12 November 1882 to 25 November 2174 — 1300–1600 AH — the answer is the Umm al-Qura calendar, tabulated by the Saudi authority. Outside those years Umm al-Qura does not exist, and the answer is the tabular Islamic calendar: arithmetic, defined for any year, and a different calendar rather than an extension of the first. The whole range runs the length of the Hijri era — 19 July 622 to 27 December 2562, AH 1–2000 — and dates before 15 October 1582 carry a Julian date too, because that is the one the records of the time were written in. How far apart the two calendars are.
To check the method: The official Umm al-Qura calendar (ummulqura.org.sa); ICU User Guide — Calendar Services; Unicode CLDR Project.
Gregorian date to Hijri
Hijri date to Gregorian
Benchmark conversions
Dates worth checking a converter against, spanning the whole era and both calendars. Each row states which calendar its conversion was made on, because the two do not always agree and a row read on its own should still say what it is.
| Occasion | Hijri date | Gregorian date (proleptic before 1582) | Julian date (before the 1582 reform) | Converted on |
|---|---|---|---|---|
| First day of the Hijri era | 1 Muharram 1 AH 1 مُحَرَّم 1 هـ | 16 July 622the calendar in use at the time | Tabular Islamic (not Umm al-Qura) | |
| Ashura — the battle of Karbala | 10 Muharram 61 AH 10 مُحَرَّم 61 هـ | 10 October 680the calendar in use at the time | Tabular Islamic (not Umm al-Qura) | |
| The sack of Baghdad | 4 Safar 656 AH 4 صَفَر 656 هـ | 10 February 1258the calendar in use at the time | Tabular Islamic (not Umm al-Qura) | |
| Start of AH 1000 | 1 Muharram 1000 AH 1 مُحَرَّم 1000 هـ | — the Gregorian date is the record | Tabular Islamic (not Umm al-Qura) | |
| First day Umm al-Qura tabulates | 1 Muharram 1300 AH 1 مُحَرَّم 1300 هـ | — the Gregorian date is the record | Umm al-Qura | |
| Start of Ramadan 1445, as announced | 1 Ramadan 1445 AH 1 رَمَضَان 1445 هـ | — the Gregorian date is the record | Umm al-Qura | |
| Eid al-Fitr 1445 | 1 Shawwal 1445 AH 1 شَوَّال 1445 هـ | — the Gregorian date is the record | Umm al-Qura | |
| Islamic New Year 1446 | 1 Muharram 1446 AH 1 مُحَرَّم 1446 هـ | — the Gregorian date is the record | Umm al-Qura | |
| Last day Umm al-Qura tabulates | 30 Dhu al-Hijjah 1600 AH 30 ذُو الحِجَّة 1600 هـ | — the Gregorian date is the record | Umm al-Qura | |
| Start of AH 1700 | 1 Muharram 1700 AH 1 مُحَرَّم 1700 هـ | — the Gregorian date is the record | Tabular Islamic (not Umm al-Qura) |
For the first centuries these are reconstructions, not records. The Islamic calendar was observational then: a month began when the crescent was actually sighted, which no rule reproduces exactly. The tabular calendar is a later arithmetic idealisation projected backwards, so an early conversion can fall a day either side of the date a history gives — and the histories themselves do not always agree. The dates above are what the arithmetic yields, stated as such. Where a source gives a different day for an early event, the source is probably reasoning from a sighting and this page from a rule, and neither is a mistake.
How far apart the two calendars are
Umm al-Qura is a printed civil calendar. The Saudi authority tabulates it for 1300–1600 AH and for no year outside that, so a converter offering dates beyond those years is either refusing or answering with something else. This page answers with something else and says so.
The something else is the tabular Islamic calendar: months alternating 30 and 29 days, with the twelfth gaining a day in eleven years out of every thirty. It is exact arithmetic and it is defined for any year, which is why it can cover the range Umm al-Qura cannot. It is not Umm al-Qura, and the difference is measurable — because for the 301 years where both are defined, both can be computed and compared.
| Tabular calendar starts the month | Months | Share of all months |
|---|---|---|
| 1 day earlier | 281 | 7.8% |
| On the same day as Umm al-Qura | 2,191 | 60.7% |
| 1 day later | 1,118 | 31.0% |
| 2 days later | 22 | 0.6% |
| Within one day either way | 3,590 | 99.4% |
So the two agree exactly on 60.7% of month starts and sit within a day of each other on 99.4%, never differing by more than 2 days. That is the cost of the wider range, stated as a number rather than as a warning. Where Umm al-Qura is tabulated, this page uses it.
What this converter does not claim
A Hijri day begins at sunset, not at midnight. Every date here is a civil day, midnight to midnight, anchored at noon UTC so that no time zone can shift it. By the reckoning most people observe, an evening falls on the following Hijri date. This page does not model sunset and cannot tell you which side of it you are on.
Observed calendars differ from printed ones. Many communities begin a month on a local sighting of the crescent, which can fall a day either side of Umm al-Qura, and practice varies by country. A printed calendar is a good answer to "what is the date" and a poor answer to "has the month begun here".
Before 15 October 1582, the Gregorian date is a back-projection. The Gregorian calendar began that day, when 4 October was followed directly by 15 October and ten days went unrecorded. Any earlier Gregorian date is the proleptic kind: exact arithmetic, but a date no document of the period carries. That is why every early conversion here shows a Julian date beside it — the Julian one is what a chronicle would have written, and the two are equally exact answers to different questions. Adoption was not simultaneous either: Britain and its colonies kept the Julian calendar until 1752 and Russia until 1918, so a source's date depends on where it was written.
The converter stops at the Hijri epoch and does not go behind it. The arithmetic would continue — the formula is defined for any year — but the calendar would not. Before the Hijra the Arabian calendar was lunisolar, with intercalary months that were later abolished, so projecting a purely lunar calendar back past AH 1 would describe a reckoning nobody kept. Dates given as "before the Hijra", the Prophet's birth among them, are also disputed in the sources rather than settled, and this site does not adjudicate that. It declines instead of publishing a date it cannot stand behind. Prose last reviewed 2026-09-04.
Looking for an age rather than a date? How old you are in Hijri years counts the anniversaries instead, and explains why a Hijri birthday moves about eleven days earlier each Gregorian year.