Do Muslims Use BC and AD — or Only Hijri Years?

The short answer

Yes — BC and AD (or the neutral equivalents BCE and CE) are in everyday use across Muslim-majority countries, because they are simply the era labels attached to the Gregorian calendar, which is the world's default for business, aviation, and international paperwork. Alongside them, the Hijri year is counted in AH years. Saudi Arabia is the clearest example: official and administrative dates are commonly given in AH, while contracts, tickets, and visas usually carry Gregorian dates too.

What each label actually marks

An era label just names the fixed starting point a year count runs from:

• AD — anno Domini, Latin for "in the year of the Lord"; BC means "before Christ" and counts backward from the same point
• CE / BCE — "Common Era" and "Before Common Era": the same numbering as AD/BC with religiously neutral wording, now standard in academic and government writing
• AH — anno Hegirae, counting from the year of the Hijrah, the migration from Makkah to Madinah; the U.S. Naval Observatory places that epoch in 622 of the Common Era

The deeper difference is not the label but the calendar underneath it. AD/CE years belong to a solar calendar; AH years belong to a purely lunar one. The Naval Observatory's introduction to calendars sorts the world's systems into solar, lunar, and luni-solar families, which is why an AH year and a CE year are not the same length and never line up cleanly.

Summary: BC/AD and CE/BCE label the Gregorian count; AH labels the Hijri count.

Is there a Hijri equivalent of BC?

There is, but it is specialist rather than everyday. Historians writing about events before the Hijrah use BH — before Hijrah — for dates on the far side of the epoch. You will see it in scholarly and biographical writing, almost never on a calendar, a form, or a wall planner. For ordinary purposes the Hijri count simply starts at 1 AH and goes up.

Summary: BH exists in historical writing; outside that, Hijri years are only counted forward.

Why both systems appear on the same document

Dual dating is a practical convention, not a compromise of principle:

• Domestic administration in Saudi Arabia has long worked in Hijri dates, so ID, residency, and official records often lead with AH
• Cross-border systems — airlines, banks, insurers, customs — are built on Gregorian dates
• Religious scheduling depends on the lunar months, which only the Hijri calendar tracks

So a single page can reasonably carry both: 1 Muharram 1447 AH next to its Gregorian equivalent. If you are reading a date written this way, what AH means after a Hijri year covers the ordering and punctuation conventions, and what Hijri year it is now shows how to confirm the current year yourself.

Summary: the two eras coexist because domestic records and international systems have different defaults.

Converting between the eras

A rough mental approximation works because the lunar year is about three percent shorter than the solar one: multiply the AH year by about 0.97 and add 622 to land in the right Gregorian year. That gets you the year, not the date — and never the day.

For anything that matters, read the boundaries off the official source, Saudi Arabia's Umm al-Qura calendar. A single AH year straddles two Gregorian years, so a conversion that returns only a year is ambiguous by design. Our guide to converting Hijri dates to Gregorian explains the common off-by-one-day disagreements, and how the Hijri calendar works covers the drift that causes them.

Summary: approximate the year with arithmetic, but take exact dates from the official calendar.