Hijri to Gregorian Date Converter
Convert Gregorian date to Hijri (Islamic) calendar.
Report Bug Living in a globalized world often requires navigating between different timekeeping systems. While the world primarily operates on the Gregorian (Solar) calendar, the Islamic world follows the Hijri (Lunar) calendar for religious observances. The Hijri to Gregorian Converter bridges this gap, allowing accurate conversion from Islamic dates (AH) to the standard international format (AD).
Since the Hijri year is 10 to 11 days shorter than the Gregorian year, dates drift annually. This tool calculates the precise alignment of these two distinct cycles.
🌙 Calculation Formula & The Lunar Shift
The conversion isn't a simple 1:1 match because the Hijri calendar depends on the moon's phases. However, the mathematical approximation used for year conversion relies on the cycle difference:
Key Variables:
- G (Gregorian Year): The solar year based on the Earth's revolution around the Sun (365.24 days).
- H (Hijri Year): The lunar year based on 12 lunar months (354.36 days).
- 622: The year of the Hijra (Migration), marking the start of the Islamic calendar.
- 0.97: The ratio representing that a Lunar year is roughly 97% the length of a Solar year.
Example Scenario: Calculating a Historical Date
To understand the drift between calendars, let's look at a conversion example. Notice how the years do not align perfectly due to the "Solar Drift."
| Calendar System | Date Details |
|---|---|
| Hijri Input (Islamic Lunar) |
1 Ramadan 1445
The start of the holy month of fasting. |
| Gregorian Output (Western Solar) |
March 11, 2024
The corresponding date in the international civil calendar. |
| The Difference (Cycle Variance) |
Approx. 579 Years
Difference in year count due to the 622 CE start date and shorter lunar years. |
Analysis: Because the Hijri year is shorter, it "travels" backwards through the Gregorian calendar seasons. Ramadan moves back by approximately 11 days each year, completing a full cycle through all seasons every 33 years.
Why Is Conversion Necessary?
Accurate conversion is critical for several aspects of life and history:
- Religious Observance: Muslims need to know when months like Ramadan, Shawwal (Eid), and Dhu al-Hijjah (Hajj) begin in the local civil calendar.
- Legal & Administrative: In countries like Saudi Arabia, official documents may use Hijri dates, which need conversion for international banking or visas.
- Genealogy & History: Researchers studying Ottoman or Islamic history often need to correlate events recorded in AH to the modern AD timeline.
Frequently Asked Questions (FAQs)
Why is the date sometimes off by one day?
The Hijri calendar is strictly lunar and traditionally relies on the physical sighting of the new moon (Hilal). While algorithms (like Umm al-Qura) provide a calculated standard, the actual religious date may vary by +/- 1 day depending on moon visibility in your specific location.
Can I convert a Gregorian date back to Hijri?
Yes, the calculation is reversible. Our tool works both ways. You can enter a future date like "January 1, 2030" to find out what Islamic month and year it will correspond to (It will be Ramadan 1451).
What is the difference between AH and AD?
AD stands for Anno Domini (Year of the Lord), based on the estimated birth of Jesus and solar cycles. AH stands for Anno Hegirae (Year of the Hijra), based on Prophet Muhammad's migration from Mecca to Medina and lunar cycles.
