How Are Ramadan Dates Determined? Moon Sighting, Hijri Calendar & Islamic Traditions (2025)

The most sacred month in Islam is Ramadan, when millions of Muslims around the world fast, pray and reflect. But how exactly are the start and end dates of Ramadan fixed?

Unlike the Gregorian calendar, which runs on a solar cycle, the Islamic Hijri calendar is lunar based, meaning it shifts dates every year.

In this Ramadan article, we explore the major methodologies of determining the start and end dates of Ramadan, such as moon sightings, astronomical calculations, and other differences within regions.

This guide will answer all your questions, whether you are a Muslim getting ready for the holy month or someone curious about Islam traditions.

What is the Hijri Calendar & How Does It Affect Ramadan Dates?

The Islamic calendar or Hijri calendar, is very important for determining the Ramadan date. Here’s how it works:

Lunar vs. Solar Calendars

• The Gregorian calendar, which is solar-based, has 365 days.
• The Hijri calendar, which is lunar-based, has 354 days, meaning each Islamic year is shorter by 11 days.
• As Ramadan is the 9th month of the Hijri calendar, its beginning and ending dates change every year in the Gregorian calendar.

Months in the Islamic Calendar

Every Islamic month has 29 or 30 days, depending on the lunar sighting. Important months associated with Ramadan are:

• Sha’ban (month just preceding Ramadan)
• Ramadan (month of fasting)
• Shawwal (a month after Ramadan starts from Eid al-Fitr)

How is the Start of Ramadan Determined Through Moon Sighting?

The Ramadan date is determined through two main methods:

Moon Sighting (Ruyat-e-Hilal)

• Islamic customs are based on direct moon sighting with the naked eye.
• Within Muslim-majority countries, religious authorities appoint moon-sighting committees.
• The next day commences if the new crescent moon is spotted.

Astronomical Calculations (Hisab)

• Some countries calculate scientifically to assess the visibility of the moon.
• While this method helps reduce discrepancies, it does face criticism from some scholars.

Regional Differences in Moon Sighting

• With local sightings, Saudi Arabia and most Gulf countries follow.
• Turkey, Malaysia, and others utilize astronomical data.
• This results in different dates for other places.

How Do Muslims Determine the End of Ramadan (Eid al-Fitr)?

The month of Ramadan ends with Eid al-Fitr, which also depends on the sighting of the Shawwal crescent moon.

Moon Sighting for Shawwal

• As with the beginning of Ramadan, scholars monitor the sighting of the Shawwal crescent moon.
• If it is sighted, Eid al-Fitr is declared the following day, marking the end of the month of fasting.

Why Do Some Countries Celebrate Eid on Different Days?

• Due to time zone differences and poor visibility, some countries may see the crescent moon before others.
• For example, Saudi Arabia may announce Eid al-Fitr one day earlier than South Asia or North America.

Common Questions About Ramadan Dates

Why Does Ramadan Move Every Year?

The Hijri calendar is lunar, so it moves 10-12 days backward in the Gregorian calendar each year.

Can Ramadan Last 28 or 31 Days?

No, Islamic months are set to either 29 or 30 days, dependent on observed moon cycles.

What If the Moon Is Not Seen?

If visibility is obstructed by clouds, a majority of countries will celebrate 30 days of Sha’ban before the Ramadan period.

FAQs About Ramadan Dates

How Many Days Is Ramadan?

Ramadan is usually 29 or 30 days but it also strictly depends on the moon sighting.

Who Decides the Ramadan Date?

Southern astronomical councils or local moon sighting committees can also set the end and start dates.

Can Technology Predict Ramadan Dates Accurately?

Some scholars prefer religious authenticity through physically sighting the moon. However, technology is advanced enough to make Ramadan predictions.

Why Do Some Muslims Fast on Different Days?

Some communities begin Ramadan a day earlier or later than others due to differences in regional moon sightings.

What Is the Earliest and Latest Ramadan Can Start?

Winter and summer are also on the table because of the lunar cycle; each year, Ramadan is pushed further and further ahead.

Do All Muslims Follow the Same Ramadan Calendar?

Not really; some await announcements from Saudi Arabia, while local sightings have jurisdiction over other groups.

How Do Muslims in Non-Muslim Countries Know When Ramadan Starts?

Most follow the guidelines set by their home country or the nearest Islamic governing body.

What Happens If the Moon Is Sighted in One Country but Not Another?

These country’s Islamic leaders operate separately and have their own rules, which may result in inconsistencies.

Is There a Unified Global Ramadan Calendar?

In one word, the answer is no. Due to variations in time zones and lack of sight visibility, it is impossible to set a unilateral date.

Can Ramadan Ever Be 31 Days?

No such thing as exceeding 30 days for Islamic months, known as the Hijri calendar, making 31 days impossible.

Conclusion

A combination of moon sighting methods and astronomical calculations defines the beginning and the end of the Ramadan month.

While some rely on physical sightings, others blend scientific predictions, which leads to variances.

From a global perception, these methods assist Muslims in preparing for the holy month while observing unity around the world during Ramadan month.

The Hijri calendar, even with traditions or technology, remains pivotal to Islamic worship.

Would you like to expand your understanding of Islamic traditions? Check out our other articles on the importance of Ramadan.