THE Islamic holy month of Ramadan begins at the sighting of the new moon in the ninth month of the lunar calendar. During Ramadan (which starts on July 9th this year) observant Muslims around the world abstain from food and drink between sunrise and sunset. Because it follows the lunar calendar, Ramadan shifts by 11 days a year in relation to the Gregorian calendar. In some places, like Saudi Arabia, that makes little difference to the number of hours a day Muslims must fast. But what happens in northern countries where there can be up to 24 hours of darkness or light, depending on the time of year? What about in Antarctica, where periods of continuous daylight and continuous darkness last several months? How do Muslims observe Ramadan in places where the sun does not set? This question has become more pressing as Muslims have ventured further afield from their original Arabian homeland, where the shortest day of the year lasts for around 12 hours and the longest for about 15. Islamic scholars have proffered various solutions. The strictest interpretation of the Koran, as argued by Saudi Arabia’s Council of Senior Scholars, maintains that one must always observe local timings as long as night is distinguishable from day, even if that means fasting for more than 23 hours a day in the summer and for just a few hours during the winter. (The photo shows Kaltouma Abakar, a refugee from Sudan's Darfur province, breaking her fast during the four-hour night in Rovaniemi, a city in northern Finland.) In those places where the sun does not set at all, one must observe the times of the nearest place where it does.

But other scholars argue that this makes for confusion over which city to follow, and that it is anyway unreasonable and not in the spirit of Islam to require people to fast for such long periods. Al Azhar Mosque in Cairo, one of the world’s most respected Islamic institutes, has ruled that Muslims should not fast for more than 18 hours a day. “We are not supposed to starve to death,” says Salman Tamimi, head of the Muslim Association of Iceland. Some communities, like the 1,000 or so Icelandic Muslims, therefore follow a fatwa (Islamic ruling) which recommends observing the fast times of the 45th parallel. Others, in Alaska and Sweden for example, instead observe the times of Mecca, since that is the place to which the Koran’s verses originally referred, a ruling backed by the European Council of Fatwa and Research. Yet another group of scholars suggests fasting for 12 hours irrespective of the time of year, because an average day offers 12 hours of sunlight.

And what of observing Ramadan from low-earth orbit, where each period of daylight lasts just 45 minutes? In 2007, when Sheikh Muszaphar Shukor, a Malaysian astronaut, became the first observant Muslim to go into space during Ramadan, Malaysia’s government published a 20-page booklet of guidelines, confirming that astronauts should follow the same prayer and fasting times as the location from which their spacecraft lifted off—in this case, the Baikonur launch pad. “There is no monolithic standard,” says Imam Abdullah Hasan of the Neeli mosque in Greater Manchester, Britain. “The beauty of Islam is its flexibility.”