The Economist explains:  How do Muslims observe Ramadan in places where the sun does not set?

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?

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