A vendor in Afghanistan sells dates ahead of Ramadan, when Muslims do not eat or drink during the day. (Rahmat Gul/AP)

Muslims around the world stocked up on groceries Wednesday for evening meals to break the sunrise-to-sundown fasting during the month of Ramadan. It is the ninth month of the Islamic calendar, dedicated to fasting, prayer and charity.

Saudi Arabia and other Muslim-majority nations, including Egypt and Indonesia, declared that Ramadan would begin Thursday. Muslims follow a lunar calendar, in which the birth of a new full moon is tracked, and it can lead to some confusion as different countries declare the start of Ramadan a day or two apart.

Mosques in the United States already declared the start of fasting Wednesday. Others will begin Thursday. Ramadan falls on especially long days this year, and Muslims in North America and Europe may not break their fast until after 8 p.m.

Food and even a sip of water must be avoided. This is intended to bring people closer to God and remind them of those less fortunate. It is also a chance to kick addictions to things such as caffeine and cigarettes. Fasting is considered obligatory in Islam, although there are exceptions for children, the elderly, the sick, those traveling and women who are pregnant and nursing. The end of Ramadan is celebrated with a three-day holiday called Eid-al-Fitr.

A Palestinian man prepares traditional sweets ahead of the holy month of Ramadan in the West Bank of Hebron on Wednesday. (Abed Al Hashlamoun/EPA-EFE/Shutterstock)