water intake during Suhur and Iftar times, which may do more harm than good. Ramadan fasting is safe for healthy people provided that overall food and water intake is adequate but those with medical conditions should seek medical advice if they encounter health problems before or during fasting. The education departments of Berlin and the United Kingdom have tried to discourage students from fasting during Ramadan, as they claim that not eating or drinking can lead to concentration problems and bad grades. A review of the literature by an Iranian group suggested fasting during Ramadan might produce renal injury in patients with moderate (GFR <60 ml/min) or severe kidney disease but was not injurious to renal transplant patients with good function or most stone-forming patients. A study on 55 professional Algerian soccer players showed that performance during Ramadan declined significantly for speed, agility, dribbling speed and endurance, and most stayed low 2 weeks after the conclusion of Ramadan. Ramadan in polar regions The length of the dawn to sunset time varies in different parts of the world according to summer or winter solstices of the Sun. Most Muslims fast for eleven to sixteen hours during Ramadan. However, in polar regions, the period between dawn and sunset may exceed twenty-two hours in summer. For example, in 2014, Muslims in Reykjavik, Iceland, and Trondheim, Norway, fasted almost twenty-two hours, while Muslims in Sydney, Australia, fasted for only about eleven hours. In areas characterized by continuous night or day, some Muslims follow the fasting schedule observed in the nearest city that experiences sunrise and sunset, while others follow Mecca time. Ramadan in Earth orbit Muslim astronauts in space schedule religious practices around the time zone of their last location on Earth. For example, this means an astronaut from Malaysia launching from the Kennedy Space Center in Florida would center their fast according to sunrise and sunset in Florida's Eastern Time. This includes times for daily prayers, as well as sunset and sunrise for Ramadan. Employment during Ramadan Muslims continue to work during Ramadan; however, in some countries, such as Oman and Lebanon, working hours are shortened. It is often recommended that working Muslims inform their employers if they are fasting, given the potential for the observance to impact performance at work. The extent to which Ramadan observers are protected by religious accommodation varies by country. Policies putting them at a disadvantage compared to