The Hijri Calendar Explained Simply: Moon Sighting & Gulf Dates
How the Islamic lunar calendar works, why Ramadan and Eid shift 10–11 days each solar year, and why Kerala dates often differ from Saudi Arabia by one day.
By Muhammed Nuhman P • Last reviewed: October 2026 • 6 min read
- Lunar System: A Hijri year consists of 12 lunar months totaling 354 or 355 days (about 10 to 11 days shorter than the 365-day Gregorian solar year).
- Annual Seasonal Drift: Because of the 10–11 day shortfall, Islamic events (Ramadan, Eid al-Fitr, Hajj) cycle backwards through all seasons every 33 solar years.
- Why Kerala & Saudi Dates Differ: Saudi Arabia often follows the calculated astronomical Umm al-Qura calendar for civil administration, whereas Kerala Hilal committees strictly require verified naked-eye sighting along the western Arabian Sea coastline.
1. The 12 Months of the Islamic Hijri Calendar
The Islamic calendar began with the migration (Hijrah) of Prophet Muhammad (peace be upon him) from Makkah to Madinah in 622 CE. Each month begins with the sighting of the new crescent moon (Hilal):
| No. | Month Name | Days | Significance |
|---|---|---|---|
| 1 | Muharram | 29 / 30 | Islamic New Year; Ashura on 10th Muharram (Sacred Month). |
| 2 | Safar | 29 / 30 | Second month. |
| 3 | Rabi' al-Awwal | 29 / 30 | Mawlid un-Nabi (Birth of the Prophet). |
| 4 | Rabi' al-Thani | 29 / 30 | Fourth month. |
| 5 | Jumada al-Awwal | 29 / 30 | Fifth month. |
| 6 | Jumada al-Thani | 29 / 30 | Sixth month. |
| 7 | Rajab | 29 / 30 | Isra and Mi'raj (Sacred Month). |
| 8 | Sha'ban | 29 / 30 | Month preceding Ramadan; Laylat al-Bara'at. |
| 9 | Ramadan | 29 / 30 | The holy month of fasting; Laylat al-Qadr. |
| 10 | Shawwal | 29 / 30 | Eid al-Fitr (1st Shawwal). |
| 11 | Dhu al-Qi'dah | 29 / 30 | Sacred month of preparation for pilgrimage. |
| 12 | Dhu al-Hijjah | 29 / 30 | Hajj pilgrimage; Day of Arafah (9th); Eid al-Adha (10th). |
2. Why Does Ramadan and Eid Often Fall on Different Days in Kerala vs Gulf?
One of the most frequent questions among expatriate families is why Eid is celebrated on Tuesday in Dubai and Saudi Arabia, but on Wednesday in Kerala. There are two primary reasons:
- Geographical Horizon & Moon Age: The crescent moon sets shortly after sunset. Because Kerala is geographically located further east (2.5 hours ahead in local solar time), the new moon is younger and closer to the sun at sunset, making it physically impossible to sight, whereas 2.5 hours later in Saudi Arabia, the moon has grown older and separated further from the horizon.
- Umm al-Qura System vs Local Sightings: Saudi Arabia's official civil calendar (Umm al-Qura) registers a new month if the moon conjuncts before sunset at Makkah and sets after the sun. Kerala's Qazis and Hilal sighting committees adhere strictly to physical, local visual sightings with eye witnesses across the Malabar coastline (Kozhikode, Ponnani, Kappad).
Frequently Asked Questions
How can I calculate my age in Hijri years?
Because lunar years are about 3% shorter than solar years (354 vs 365 days), a person who is 33 Gregorian years old is approximately 34 Hijri years old. For every 33 solar years lived, you add roughly 1 additional lunar year.
Use our Hijri Date Converter and Age Calculator for instant conversions.