Why Is the Islamic Year 11 Days Shorter? What It Means for Ramadan and Eid

Every year someone notices that Eid has come “early” again. It has — by about eleven days. The Islamic year is shorter than the Gregorian year by a fixed, predictable amount, and once you understand where that gap comes from you can predict next year’s Ramadan in your head.

The numbers behind the gap

The Gregorian calendar follows the sun. A solar year — the time from one spring equinox to the next — lasts about 365.2422 days, which is why the Gregorian calendar has 365 days with a leap day most fourth years.

The Hijri calendar follows the moon. The time from one new moon to the next averages 29.5306 days. Twelve of those make:

12 × 29.5306 = 354.367 days

The difference:

365.242 − 354.367 = 10.875 days

So, on average, each Hijri year ends about 10.9 days before the corresponding solar year. Because real Hijri years are whole numbers of days — 354 or 355 — individual years differ by 10 or 11 days, but the long-run average is just under 11.

Why the Hijri calendar does not correct for the sun

Most lunar calendars in history did correct the drift. The Hebrew and traditional Chinese calendars, for example, insert a thirteenth month about every three years so that festivals stay in their seasons. Pre-Islamic Arabia did something similar.

The Islamic calendar deliberately does not. The Quran fixes the number of months at twelve (9:36) and condemns the practice of postponing months, nasi’ (9:37). The result is a calendar that is tied only to the moon.

What the 11-day drift looks like in practice

The table shows the expected start of Ramadan on the Umm al-Qura calendar for the next few years.

Year	Ramadan begins	Shift
2025 (1446 AH)	1 March 2025	—
2026 (1447 AH)	18 February 2026	11 days earlier
2027 (1448 AH)	8 February 2027	10 days earlier
2028 (1449 AH)	28 January 2028	11 days earlier

The same 10–11 day step applies to every Islamic date: Eid al-Adha moves from 27 May 2026 to 16 May 2027, the Islamic New Year from 16 June 2026 to 6 June 2027.

Every season, every 33 years

If something moves 10.9 days a year through a 365-day year, it takes about 33.6 years to come all the way round. In practice the full cycle is about 33 Gregorian years — which equals about 34 Hijri years.

That means:

• Ramadan visits every season over a lifetime. Someone who fasted long summer days as a teenager will fast short winter days in middle age.
• Within a decade, the change is noticeable. Ramadan in 2017 began in late May; in 2027 it begins in early February.
• Hemispheres balance out. A summer Ramadan in Europe is a winter Ramadan in Australia, and both reverse over the cycle.

Many scholars point to this as a quiet fairness built into the calendar: no region is permanently assigned the longest fasting days.

A quick rule for predicting next year

You can estimate any Islamic date next year with one subtraction:

Next year’s date ≈ this year’s date − 11 days (sometimes 10)

Eid al-Fitr 2027 is expected on 9 March. Subtract 11 days and you get 26 February — and Eid al-Fitr 2028 is indeed expected on 26 February 2028.

The estimate can be off by a day for two reasons: the Hijri year may be 354 or 355 days, and the observed start of the month depends on the crescent.

The drift and your age

Because Hijri years are shorter, your age in Hijri years is higher than in Gregorian years. The rule of thumb is that your Hijri age gains a year on your Gregorian age roughly every 33 years:

Gregorian age	Approximate Hijri age
15	15–16
33	34
50	51–52
66	68

This has practical relevance — some Islamic legal and financial matters, such as the passing of a lunar year (hawl) for zakat, are reckoned in Hijri time. The Hijri age calculator gives an exact figure.

Zakat and the lunar year

Zakat on savings is due when wealth above the threshold (nisab) has been held for a full lunar year. Many people calculate it on a fixed Gregorian date for convenience. Because the solar year is about 11 days longer, scholars who allow a Gregorian zakat date generally recommend adjusting the rate slightly — commonly from 2.5% to about 2.577% — to compensate for the longer year. If you use a Gregorian date, ask a scholar you trust which approach they recommend.

Does the drift ever stop?

No. With no intercalation, Hijri dates keep moving through the solar year forever. The Hijri year number, meanwhile, slowly catches up with the Gregorian number. Today the gap is 578 years (2026 vs 1448); in 622 CE it was 621. It shrinks by roughly one year every 33 years.

What the drift does to fasting hours

The season Ramadan falls in matters most for one practical thing: how long each fast lasts. Fasting runs from dawn (Fajr) to sunset (Maghrib), and the length of daylight depends on the season and on how far you live from the equator.

Take the first day of Ramadan 1448, 8 February 2027, calculated with each city’s usual method:

City	Fajr	Maghrib	Fast length
London	05:34	17:02	about 11½ hours
New York	05:42	17:22	about 11¾ hours
Karachi	05:53	18:22	about 12½ hours
Makkah	05:38	18:15	about 12½ hours

Compare that with a midsummer Ramadan. When Ramadan fell in June in the late 2010s, London’s fasts ran from about 02:30 to 21:20 — close to 19 hours. In the coming years, as Ramadan slides through winter, European and North American fasts will be at their shortest. In the southern hemisphere it is the reverse: Sydney and Johannesburg are moving towards their longest Ramadan days.

Near the equator — Jakarta, Kuala Lumpur, Lagos — daylight barely changes through the year, so fasts stay around 13 hours whatever the season.

How other calendars handle the same problem

The Islamic calendar is not unusual in using the moon; it is unusual in refusing to correct for the sun. A comparison makes the choice clear:

Calendar	Based on	How it stays in season
Gregorian	Sun	Leap day in most fourth years
Hebrew	Moon and sun	Extra month 7 times every 19 years
Traditional Chinese	Moon and sun	Extra month about every 3 years
Solar Hijri (Iran)	Sun	Months fixed to the solar year
Islamic (Hijri)	Moon only	It doesn’t — dates move through the seasons

The Hebrew and Chinese approach is called lunisolar. It keeps festivals like Passover or Chinese New Year within a month-long window of the solar year. The Islamic calendar gave that up deliberately.

Three common misconceptions

“The Islamic calendar is losing days.” It is not losing anything. Each month is exactly as long as the moon’s cycle. It only looks like loss when you measure a lunar calendar against a solar one.

“Eid is getting earlier because of a calculation change.” No — every Islamic occasion moves earlier every year by the same 10–11 days. Nothing about the method has changed.

“A Hijri date always falls in the same season.” This was true in pre-Islamic Arabia, when an extra month kept the calendar aligned. It has not been true for nearly 1,400 years.

Practical takeaways

• Islamic dates are about 11 days earlier each Gregorian year. Planning for Ramadan or Eid? Start from last year’s date and subtract 11.
• The exact day still depends on the moon. Calculated dates are reliable for planning, but the final start of Ramadan and the Eids is confirmed by sighting or official announcement.
• Long-term planning is easy. You can look several years ahead — the Islamic holidays page lists the expected dates for the current and next Hijri year.

The 11-day gap is not an irregularity. It is the calendar doing exactly what it was designed to do: follow the moon, and let the seasons take care of themselves.