We used sunrise and sunset timings in major cities of these countries to calculate the intervals between Fajr (preceding sunrise by 90 minutes) and Maghreb (marking sunset) on the first day of Ramadan, May 17.
In countries where sunset and sunrise are too close (less than 3 hours apart) or are indistinguishable, fatwas have been issued to allow Muslims to follow the timings of the closest city that has have distinguishable day and night timings.
Note: These timings are of the expected first day of Ramadan only.
The longest fast in Europe based on our findings is in Iceland with just four hours of night time, while Spain, Turkey and other countries have comparatively lower intervals, ranging around 16 hours of fasting.
Greenland being the northern-most country in the Americas has the longest interval between Fajr and Maghreb at 20 hours and 8 minutes.