Science and religion don’t often tread he same path, and when ever they do, there is some astronomy involved in a rather teasing manner.
Practising muslims observe fast in the islamic month of ramadan, in simple words they don’t eat anything while the sun is out on the horizon. Islamic calender is a lunar one. This means the Islamic months are quite not pegged to the Gregorian calender which owes its allegiance to sun. This results in Islamic months rotating in relation to the gregorian months. For example: The month of ramadan in year X might be in Gregorian october, in X+1 it moves forward by a few days to probably september and after a cycle of N years will be back in October.
While most of practising muslims live in the tropics to lower latitudes, where the length of days and nights is equal through out the year. But for the few, living at higher latitudes, fasting poses a challenge. So a practicing muslim in Northern Europe may only need to fast for 7 hours when Ramadan falls in January (Northern hemisphere winter) , one may have to fast for almost 15 hours if ramadan falls in June/July. When one goes to even higher latitudes north of Arctic circle (or south of antarctic circle), say to cities in northern Norway /Sweden, the sun is on the horizon 24 hours a day in june and never on the horizon in january, bringing the might of religion against more humble geometrical 23.5 degree tilt of earth.
(A curious search on google says there are different views in Islam to this problem. The solutions it seem range from following Mecca standard time to following the time of nearest city where sun actually sets / rises to following a swiss made clock instead of solar clock.)
