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. The new moon, which marks the start of Ramadan, was sighted in Saudi Arabia, Indonesia, Singapore, Yemen, Lebanon, Syria, Qatar, Kuwait, Jordan, Egypt, the United Arab Emirates, Afghanistan and the Palestinian territories, among others.

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Indonesian Muslims hold prayers to mark the start of the holy month of Ramadan at the Baiturrahman mosque in Banda AcehChaideer Mahyuddin/AFP

Muslims follow a lunar calendar and a moon-sighting methodology that can lead to different countries declaring the start of Ramadan a day or two apart. By Sunday evening, Pakistan and Iran had yet to officially announce Monday as the first day of Ramadan. Traditionally, countries announce if their moon-sighting council spots the Ramadan crescent the evening before fasting begins.

The faithful spend the month of Ramadan in mosques for evening prayers known as "taraweeh", while free time during the day is often spent reading the Quran and listening to religious lectures. 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.

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A Muslim man uses a telescope to observe the moon before the Muslim holy month of Ramadan at Al-Musyari'in mosque in Jakarta, IndonesiaIqro Rinaldi/Reuters
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A Muslim man uses tools to check for the position of the moon at the start of the Muslim holy month of Ramadan at Jerman beach, Kuta, IndonesiaAntara Foto/Reuters
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Bahraini men look at the sky to spot the first crescent moon marking the start of the Muslim holy month of Ramadan, in the village of Karzakkan, south of ManamaMohammed al-Shaikh/AFP
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A man looks at the sky to spot the crescent moon marking the start of the Muslim holy month of Ramadan in the village of Karzakkan, south of Manama, BahrainMohammed al-Shaikh/AFP
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The new crescent moon is seen above the Margala Hills to mark the begining of the of the Islamic holy month of Ramadan in Islamabad, PakistanAamir Qureshi/AFP
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Muslims attend the Ramadan taraweeh prayer at Istiqlal mosque in Jakarta, IndonesiaBeawiharta/Reuters
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A man wakes up residents for their pre-dawn meals during the first day of Ramadan in Cairo, EgyptAmr Abdallah Dalsh/Reuters
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Children break their fast on the first day of the holy Islamic month of Ramadan in Kuala Lumpur, MalaysiaManan Vatsyayana/AFP
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Syrian children attend a lecture at a mosque in Kafr Batna, in the rebel-held Eastern Ghouta area, on the outskirts of the capital DamascusAmer Almohibany/AFP
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Bboys read copies of the Quran on the first day of the holy month of Ramadan at a mosque in Tangerang, IndonesiaAdek Berry/AFP
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A Turkish band plays music welcoming the holy fasting month of Ramadan in Tripoli, LebanonOmar Ibrahim/Reuters
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A salesman hangs religious pictures for sale ahead of the Muslim fasting month of Ramadan in Kolkata, IndiaRupak de Chowdhuri/Reuters
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A man and children play traditional drums as they take part in the Musaharati, a Ramadan tradition where drummers wake people for the meal before the day’s fast, in Beirut, LebanonJamal Saidi/Reuters
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Palestinian youths play at sunset at Al Khalde mosque in the Gaza town of JabaliyaMajdi Fathi/Nur Photo/Getty Images
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Palestinians take part in a celebration ahead of the beginning of the Muslim holy month of Ramadan in Gaza CitySaid Khatib/AFP
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People buy dates from a shop at a market in Karachi, Pakistan, on the eve of the Islamic holy month of RamadanAsif Hassan/AFP
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Indonesian Muslims hold prayers to mark the start of the holy month of Ramadan at the Al Akbar mosque in SurabayaJuni Kriswanto/AFP
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A Palestinian man decorates his shop with lights near the entrance of the Al-Aqsa mosque compound, in the old city of JerusalemAhmad Gharabli/AFP
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A Yemeni vendor goes through red lentils at a market in the old city of the capital SanaaMohammed Huwais/AFP
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Muslims gather to spot the first crescent moon, marking the start of the holy month of Ramadan, in Thailand's southern Yala ProvinceMadaree Tohlala/AFP
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Iraqis do some shopping ahead of Ramadan at Shorja market in BaghdadSabad Arah/AFP
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A Palestinian vendor sells traditional lanterns in Gaza CityMahmud Hams/AFP
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A man carries sweets at a factory ahead of the Islamic holy month of Ramadan in Jalalabad, AfghanistanNoorullah Shirzada/AFP
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A Palestinian man decorates his shop with lights in the old city of JerusalemAhmad Gharabli/AFP

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.