Muslims in Southeast Asia and much of the Middle East will start their Ramadan fasts on Monday while those in places like India, Pakistan and Iran will likely start Islam's holy month on Monday, AP reported. 

“Muslims follow a lunar calendar, and a moon-sighting methodology can lead to different 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.

Across the world, Muslims fast each day for the entire month of Ramadan, abstaining from food and drink from dawn to dusk. That means around 15 hours without food, water, cigarettes or caffeine.

Fasting is aimed at drawing worshippers closer to God through self-control, remembrance and humility. The challenge of fasting for many is also a chance to reset spiritually and physically, kick bad habits and purify the heart,” the source noted.

Over 1.5 billion Muslims off all around the world will observe fasting in the coming month, which is considered one of the five pillars of Islam.