Fasting during Ramadan is one of the five pillars of Islam, and all healthy adult Muslims are obliged to refrain from eating and drinking from sunrise to sunset during this lunar month. The fast may last 11–19 hours, depending on where and at what time of year Ramadan occurs. People with an acute illness such as flu may postpone fasting to other days when their illness has resolved. People with chronic illnesses such as diabetes are not obliged to fast and can donate to a charity as atonement – however, many still choose to fast.
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