Many of the UK's 2.7milion Muslims will have greeted the arrival of this week's long summer days with a resigned shake of the head.
This week marks the beginning of Ramadan, and it looks set to be one of the toughest fasts in decades, with 18 hours of daylights during which observant Muslims cannot let food or drink pass their lips.
Those observing must wake at 2.30am to eat before the sun rises, and can only eat again at 9pm that evening, celebrating the 'iftar', the meal which breaks the fast, usually by eating dates.
Some Muslims in Scandinavian countries, where daylight can last almost 24 hours, have chosen to observe the sunrise and sunset times in Mecca.
But one Muslim scholar in Sweden issued guidance this year insisting Muslims continue to fast all day, despite the near constant sunlight.
"There is still day and night, so Muslims should just follow the rule that you fast during the hours of daylight. Sometimes Ramadan falls in the winter, and then the hours of daylight are very short,” Sheikh Mahmoud Khalfi said.
Imam Abdul Mannan, president of the Islam Society of Northern Finland, said Muslims could choose what to observe, according to an Emirati newspaper.
"The Egyptian scholars say that if the fasting days are long - more than 18 hours - then you can follow the Mecca time or Medina time, or the nearest Muslim country time,” he said.
“There is still day and night, so Muslims should just follow the rule that you fast during the hours of daylight. Sometimes Ramadan falls in the winter, and then the hours of daylight are very short,” Sheikh Mahmoud Khalfi said.
On the opposite end of the planet, Muslims in such countries as Argentina and Australia have an easier time, with an average day of only around nine to 10 hours
Thousands of tweets have been sent by Muslims and well-wishers across the globe, wishing a Ramadan Mubarek.
This goes to all my muslim Friends: have a nice and contemplative Ramadan. Poldi
Ramadan MubarakJuly 9, 2013
The religious holiday was created as a Holy Month after the first Qur'an was shown to the Prophet Muhammad, later known as the Night of Power or Laylat al-Qadr.
Channel 4 announced last week that it would broadcast the Muslim call to prayer every morning during Ramadan - a decision which the broadcaster called a "provocation" to those who only associate the religion with terror and violence.
The start of Ramadan depends on the sighting of the moon. Different Muslim communities will start the month depending on their interpretation of moon sighting.
During this month of intermittent fasting, Muslims don't eat, drink, smoke or perform sexual intercourse from dawn to dusk and spend time doing their usual day-to-day duties along with prayer and reading spiritual texts.
Over a billion Muslims all over the world observe a month of fasting, charity and solidarity, with many British mosques opening their doors to the public and inviting in neighbours to join evening meals to break the fast.
The Muslim Council of Britain has issued guidance to those fasting for such long periods, and in such hot weather.
"It is important that whilst Muslims observe the fast, health is not ignored. The Council has issued a ‘Ramadan Health Fact Sheet’ that has been circulated to chaplains across hospitals in the UK, as well as a guidance document on ‘Ramadan and Diabetes - A Guide for Patients'," a spokesman said.