By Ramadaninfo.com

Because the Islamic (Hijri) calendar is lunar, its year is shorter than the Gregorian solar year. Encyclopaedia Britannica explains that an Islamic year totals 354 or 355 days, which is why Islamic months “move” earlier over time when mapped onto Gregorian dates.

What this means in practice

A difference of roughly 10–11 days per year adds up across decades. If Ramadan shifts earlier by about ~11 days each year, then over ~33 years it moves earlier by about one full year (11 × 33 ≈ 363 days). Gulf News notes this seasonal cycle repeats roughly every 33 years, which is why “double Ramadan” years occur.

The projected Ramadan dates in 2030

Calendar projections commonly place:

• Ramadan 1451 AH beginning in early January 2030
• Ramadan 1452 AH beginning again in late December 2030

For the UK, timeanddate lists Ramadan Start (tentative) as Sunday 6 January 2030 and again as Thursday 26 December 2030.
Regional calendars may show a one-day difference (for example, Gulf News describes the first start as 5 January and the second as 26 December).

Important: these are projections—Gulf News also stresses that the official start is determined by crescent moon sighting, so dates can vary by location and method.

Has this happened before—and when will it happen again?

Yes. A documented example is 1997, when Ramadan began on 10 January 1997 (1 Ramadan 1417) and then began again on 30 December 1997 (1 Ramadan 1418). Al Arabiya reports the next similar occurrence after 2030 is expected in 2063.

Why it’s “rare” but not mysterious

As Dubai Astronomy Group’s Hassan Ahmed Al Hariri explained to Gulf News, this outcome is simply the result of two calendars running on different systems—solar vs. lunar.