InputTestHub

Hijri to Gregorian Date Converter

Converts between Hijri and Gregorian dates in both directions using the tabular Islamic calendar, with the year's notable days.

Converters Nothing uploaded No sign-up Free, unlimited
Converters tool
YYYY-MM-DD
Enter your figures and press Calculate.
In short Hijri to Gregorian Date Converter is a free online tool on inputtesthub.com that converts between Hijri and Gregorian dates in both directions using the tabular Islamic calendar, with the year's notable days. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.

How to use the Hijri to Gregorian Date Converter

  1. Enter your figures in the input fields.
  2. The result updates as you type, together with the full working.
  3. Check the breakdown table to see exactly how the number was reached.

About the Hijri to Gregorian Date Converter

The Hijri to Gregorian Date Converter converts between Hijri and Gregorian dates in both directions using the tabular Islamic calendar, with the year's notable days. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.

What people use it for

  • Converting a date of birth between calendars.
  • Working out when Ramadan falls in a Gregorian year.
  • Filing a record that needs both dates.

Details

Hijri year354 or 355 days
DriftAbout 11 days a year
Epoch16 July 622 CE
Cycle11 leap years in 30
Observed datesCan differ by a day or two

The maths behind it

This tool uses the tabular Islamic calendar: a 30-year cycle of 11 leap years, epoch 16 July 622 CE, converted through the Julian day number so both directions are exact inverses. Every intermediate value is shown on screen, so the result can be checked by hand.

The tabular calendar is exact as arithmetic and approximate as a calendar. That distinction is the whole point: it gives the same answer everywhere and to everyone, which is what makes it useful for records and useless for religious obligation.

Where this tool stops

It implements the civil variant of the tabular calendar, with the epoch at 16 July 622 CE. The astronomical variant starts a day earlier, so dates from other converters can differ by one for that reason alone, before any question of moon sighting.

Explained in our guides

All guides

Frequently asked questions

Why does this date differ from my local calendar by a day?
Because most countries begin a month on the sighting of the crescent moon, which no formula can predict. This uses the tabular calendar — arithmetical, reversible and identical on every device — so it can sit one or occasionally two days either side of the observed date, and two countries can differ from each other on the same day.
Can I use this to know when Ramadan starts?
For planning, yes; for the obligation, no. The table shows where 1 Ramadan falls in the tabular calendar, which is close enough to book leave around. The actual start is announced locally after a sighting, and that announcement is what to follow.
Are there any usage caps on the Hijri to Gregorian Date Converter?
There is no cost and no cap. The Hijri to Gregorian Date Converter is not a demo of a paid product, so nothing is held back or watermarked.
Does anything I enter leave my computer?
No. The Hijri to Gregorian Date Converter runs entirely in your browser using JavaScript. Nothing is transmitted, logged or stored, which you can verify yourself in the Network tab of your browser's developer tools.
What formula does the Hijri to Gregorian Date Converter use?
It uses the tabular Islamic calendar: a 30-year cycle of 11 leap years, epoch 16 July 622 CE, converted through the Julian day number so both directions are exact inverses. The full working is printed under the result, so you can follow every step rather than trusting a black box.
What is the Hijri to Gregorian Date Converter used for?
Typical uses: converting a date of birth between calendars. Working out when Ramadan falls in a Gregorian year. Filing a record that needs both dates. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is there anything the Hijri to Gregorian Date Converter cannot do?
It implements the civil variant of the tabular calendar, with the epoch at 16 July 622 CE. The astronomical variant starts a day earlier, so dates from other converters can differ by one for that reason alone, before any question of moon sighting. Knowing where a tool stops being trustworthy matters more than the cases where it works.
What figures does the Hijri to Gregorian Date Converter work from?
Hijri year is 354 or 355 days. Drift is About 11 days a year. Epoch is 16 July 622 CE. These are printed on the page itself, so you do not have to take them on trust.
Can I rely on this for exact work?
The calculation runs in double precision and the result is shown to ten significant figures, so converting a value and converting it back returns the original. What is displayed is rounded for readability; what is copied is not.

Related converters tools

All 1079
01

Number Base Converter

Converts numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, in…

02

Roman Numeral Converter

Converts numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3,999,999.

03

Shoe Size Converter

Converts shoe sizes between US, UK, EU, Japan and centimetres for men, women and children.

04

Ring Size Converter

Converts ring sizes between US, UK, EU and Japan systems and shows the matching inside…

07

Bra Size Converter

Converts bra sizes between UK, US, EU, France, Italy, Australia and Japan, or works the size…

09

Hat Size Converter

Converts head circumference to US, UK and EU hat sizes using the real formula: the size is the…

10

Glove Size Converter

Converts hand circumference to glove size and letter size for men and women. The glove size is…