Wednesday was the first day of Ramadan for most Muslims. Around the world hundreds of millions have begun observing the holy month.
For many in the Middle East, the dawn-to-dusk fast poses a particular challenge amid a sweltering heatwave.
In Israel soldiers have been told not to eat, drink or smoke in front of Arabs out of respect.
In Gaza, where most people depend on food handouts, the authorities were planning to distribute parcels to 13,000 families of unemployed workers and prisoners held by Israel.
The extreme heat has prompted the Palestinian territories, like Jordan and Lebanon, to shorten the working day for civil servants.
Egypt has joined them in moving its clock back an hour to allow people to break their fast earlier in the evening.
A Cairo-based newspaper described the start of Ramadan as the most difficult for years, due to high prices, power cuts and soaring temperatures.