Ramadan 2025 is well under way, and Muslims worldwide remain committed to fasting throughout the month. However, while fasting is a defining aspect of the month, its duration is not fixed. Observers must abstain from food, drink, and other physical needs from dawn (fajr) until sunset (maghrib), but the length of this fast varies depending on location. This variation is due to the Earth’s tilt and orbit around the Sun, which influence the length of daylight hours.
Additionally, because Ramadan follows the Islamic lunar calendar, which is roughly 10–12 days shorter than the Gregorian calendar, its timing shifts annually, affecting fasting durations even further.
The length of the fast in any given location is determined by the time between dawn and sunset. Fasting hours do not vary much in equatorial regions such as Singapore, Somalia and Colombia, where daylight hours remain relatively consistent throughout the year. However, in places at higher latitudes such as Scandinavia, Canada, or parts of Russia, the length of the fast varies dramatically. The same is true for lower latitudes, such as South Africa, Australia and Argentina.
For example, in cities near the equator, such as Jakarta and Nairobi, fasting hours remain relatively steady at around 12–13 hours a day.
In contrast, in northern cities such as Reykjavik and Tromso, fasting hours can extend well beyond 18 or even 20 hours in winter. In some extreme cases, where the Sun does not set or rise fully (such as in parts of northern Finland and Sweden during summer and winter months), scholars recommend following the fasting hours of Makkah or a nearby moderate location.
Ramadan lasts approximately 29 or 30 days, depending on the sighting of the crescent moon. During this month, fasting hours change gradually as the Earth continues its orbit around the Sun. Because Ramadan is not fixed to a specific season in the solar calendar, the extent of change within the month depends on a location's latitude and the season in which it falls.
For instance, if Ramadan occurs in April or May, countries in the Northern Hemisphere experience increasing daylight hours as they move towards summer, meaning fasting times lengthen slightly each day. At the same time, fasting hours gradually decrease in the Southern Hemisphere, where the days are shortening towards winter.
