Muslims around the world are marking the start of the holy month of Ramadan, a time marked by intense prayer, dawn-to-dusk fasting and nightly feasts. Muslims follow a lunar calendar and use the sighting of the new moon to determine the start of the month, which can lead to countries declaring the start of Ramadan a day or two apart. Traditionally, countries announce if their moon-sighting council spots the Ramadan crescent the evening before fasting begins.

Each day for the month of Ramadan, Muslims abstain from eating and drinking from sunrise to sunset. Even a sip of water, coffee or a cigarette can invalidate one's fast. There are exceptions to fasting for children, the elderly, the sick, women who are pregnant, nursing or menstruating, and people travelling.

Many break their fast as the Prophet Muhammad did around 1,400 years ago, with a sip of water and some dates at sunset followed by prayer. It is common for Muslims to break their fast with family and friends and charities organise free meals for the public at mosques and other public spaces. The fast is intended to bring the faithful closer to God and to remind them of the suffering of those less fortunate.

Giving to charity is an important part of the holy month of Ramadan. There are two types of charity known as Zakat (a fixed amount of savings donated to the poor, mandatory as one of the pillars of Islam) and Sadaqa (voluntarily giving above and beyond the mandatory amount).

Islam is the second-largest religion in the world with roughly 1.6 billion followers around the world –nearly a quarter of the global population. Ramadan is the ninth month of the Islamic calendar and observing it is one of the Five Pillars of Islam. It is a period of fasting, prayer and charitable giving believed to mark the first revelation of the Quran to the prophet Muhammad.