Calculated via the Aladhan API's astronomical method. Last checked September 2026, see Methodology & Sources.
Why Hijri dates can shift by a day
The Islamic Hijri calendar is a lunar calendar of twelve months, traditionally tied to physical moon sighting rather than a fixed astronomical rule. That means a calculated date (like the one this tool produces) is a very close estimate, but the locally announced date for the start of a month can differ by a day depending on where and how the moon is sighted. In Bangladesh, the Islamic Foundation Bangladesh coordinates the national moon-sighting committee and announces the official start of Ramadan, Eid-ul-Fitr, and Eid-ul-Adha each year. For statutory leave dates, see our official Public Holidays Gazette (সরকারি ছুটির তালিকা).
The twelve Hijri months
The Hijri year runs Muharram, Safar, Rabi' al-awwal, Rabi' al-thani, Jumada al-awwal, Jumada al-thani, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qi'dah, and Dhu al-Hijjah, each roughly 29 or 30 days, making the Hijri year about 10–11 days shorter than the Gregorian year. That's why Ramadan, Eid, and other Islamic dates shift earlier each year on the Gregorian calendar.
Why the Hijri year has no leap days
Unlike the Gregorian calendar, which adds a leap day roughly every four years to stay aligned with the solar year, the Hijri calendar is purely lunar and doesn't adjust to match the solar cycle at all. Twelve lunar months add up to about 354 or 355 days, roughly 10 to 11 days short of a full solar year, and that gap compounds year after year rather than being corrected. Over about 33 Gregorian years, the Hijri calendar cycles through all four seasons relative to the Gregorian date, which is why a birthday or anniversary on the Hijri calendar visibly drifts earlier each Gregorian year if you track it.
Common uses for this converter
People typically use a Hijri converter to check a Gregorian birth date against Islamic records, plan roughly when Ramadan or Hajj season will fall in a given Gregorian year, convert a date on an old document or gravestone, or simply satisfy curiosity about what today's date is on the Islamic calendar. To synchronize your daily schedule with Islamic prayer hours, check our Prayer Times (নামাজের সময়সূচি). To view Bengal's traditional solar dates, visit our Bangla Calendar & Panjika (বাংলা ক্যালেন্ডার), and to calculate your annual obligatory charity on wealth and gold, use our Zakat Calculator (জাকাত ক্যালকুলেটর).
FAQ
- Why can Hijri dates be off by a day?
- Because the Hijri calendar is traditionally based on physical moon sighting, which can vary by location and local announcement, a calculated astronomical date can differ from the officially announced date by a day, especially around Ramadan and Eid.
- Who announces the start of Ramadan and Eid in Bangladesh?
- The Islamic Foundation Bangladesh coordinates the national moon-sighting committee and issues the official announcement for the whole country.
- How many months are in the Hijri calendar?
- Twelve lunar months, including Ramadan (the ninth) and Dhu al-Hijjah (the twelfth, during which Hajj takes place), each about 29 or 30 days long.
- Should I use this tool to decide when Ramadan starts?
- Use it for planning and general reference, but follow the official announcement from the Islamic Foundation Bangladesh or your local mosque for religious observance, this is a calculated estimate, not a religious ruling.
- Why does the Hijri calendar have no leap year?
- It is a purely lunar calendar with no adjustment to match the solar year, unlike the Gregorian calendar's leap day. This means Hijri dates drift earlier relative to the Gregorian calendar by about 10 to 11 days every year.
- Is this converter free?
- Yes, free to use, with no sign-up required.