You need a Hijri date for a contract, an invoice or an official document, and you end up hunting through calendars and converters. Converting between the Gregorian and Hijri calendars is a daily task across the Arab world — and many sites make it harder than it needs to be.
This guide shows how to convert in both directions inside your browser, accurately, without sending any data anywhere.
Why the conversion is not simple arithmetic
Many assume a fixed number of days separates the two calendars. It does not, for two reasons:
- The Hijri calendar is lunar: a month begins with the sighting of the crescent and lasts 29 or 30 days — it varies month to month.
- The lunar year is shorter: 354 or 355 days against 365 or 366. That is a drift of roughly 11 days every year.
So an accurate conversion needs an agreed tabular or astronomical basis, not addition and subtraction.
Astronomical Hijri or sighting-based Hijri?
This is the point most converters skip:
| Type | Basis | Used for |
|---|---|---|
| Astronomical (Umm al-Qura) | An agreed astronomical calculation | Official documents in Saudi Arabia and several states |
| Sighting-based | The actual sighting of the crescent | Religious occasions — may differ by a day |
That is why two converters can disagree by one day. For official documents use the astronomical result; for religious occasions follow the competent authority.
How to convert inside your browser — step by step
Step 1: open the tool
Go to TaskDo's Hijri/Gregorian date converter. No signup.
Step 2: pick a direction
Choose Gregorian to Hijri or the reverse. It works both ways.
Step 3: enter the date
Type day, month and year, or pick from the date selector.
Step 4: read the full result
You get the corresponding date with the month name and weekday — not just numbers.
Local processing vs sites that want your data
| Criterion | In your browser (TaskDo) | A server-side site |
|---|---|---|
| Where the work happens | On your device | On a third party's server |
| The dates you enter | Never transmitted | Usually logged with the request |
| Repeated lookups | Invisible to anyone | Build a profile of your interests |
| Works after page load | Works offline | Does not work |
A single date looks harmless — but patterns of lookups (contract dates, appointments, occasions) add up to a picture of your activity.
Common mistakes
- Assuming a fixed offset: there is none; the lunar year is about 11 days shorter.
- Trusting one converter for religious dates: sighting may differ from calculation by a day.
- Omitting the calendar in contracts: always write it explicitly — "15 Ramadan 1447 AH" or "15 March 2026 CE".
- Archiving a Hijri date alone: add the Gregorian equivalent beside it to avoid later confusion.
Practical tips
- Double-check contract dates: a wrong date in a contract can be costly.
- State the calendar explicitly: write AH or CE after every date in a shared document.
- Save your recurring conversions: note fixed dates (fiscal year start, annual deadlines).
- Know which Hijri you need: decide between astronomical and sighting-based before relying on a result.
Frequently asked questions
Are the dates I enter sent anywhere?
No. The conversion runs entirely in your browser and no date is transmitted to anyone.
Is the conversion astronomical or sighting-based?
The tool uses the agreed astronomical calculation (Umm al-Qura), which is what official documents use. For religious occasions the sighting may differ by a day.
Can I convert Hijri to Gregorian?
Yes, it works in both directions with the same accuracy.
Does it show month names and weekdays?
Yes, the result includes the numeric date, the month name and the weekday.
Is there a limit on conversions?
No, use it as much as you like.
Does it work on a phone?
Yes, on any device with a modern web browser.
Related tools
- Age calculator — your age in years, months and days
- Number to words — spell amounts out for contracts and invoices
- Percentage calculator — discounts and taxes
- Unit converter — length, weight, temperature
Summary
An accurate conversion is not addition and subtraction — the lunar year is about 11 days shorter and the difference compounds. And the key idea: your dates are your business.