It was already clear that it would be a question of whether it would be possible tonight, but no crescent moon was spotted tonight in Saudi Arabia, which means that Ramadan ends tomorrow night and not tonight.
Not all Muslims keep the traditional calendar. Turkish Muslims, for example, assume a calculation of the moon phases over Ankara. It has been clear to them for some time that the month of fasting ends tomorrow evening. Most Moroccan Dutch people use the traditional calendar.
During Ramadan, Muslims are not allowed to eat, drink, smoke or have sex during the day for a month. Fasting begins just before the sun rises. In the past month, that was around 4:00 AM. Participants are only allowed to eat and drink again at evening prayer, which was around 9 p.m. this year.
During the month of fasting, Muslims have to do extra charity. The sick, pregnant women, young children and travelers do not have to fast.
The period of Ramadan is shifting because the Islamic calendar is based on the position of the moon. A few years ago, Ramadan fell in the middle of summer, in 2030 Ramadan starts around Boxing Day.