The UAE's Moon-sighting committee will meet on Tuesday evening to determine the start of Ramadan.
If the new crescent is spotted, fasting will begin at dawn on Wednesday.
If the spotters cannot see it due to clouds, they will meet the following evening and fasting will not begin until Thursday at the earliest.
The committee will meet after the Maghreb prayer at the Abu Dhabi Judicial Department.
The meeting will be attended by several high-ranking officials and led by Abdullah Al Nuaimi, Minister of Justice.
According to Wam, Sharia courts across the country will monitor and notify the committee of any sightings, while the Lunar Calendar Committee will report its findings to the Moon-sighting Committee.
On Sunday, the Supreme Court in Saudi Arabia called on the public to look for the crescent Moon from Tuesday.
Ramadan is observed by more than 1.8 billion Muslims and is believed to be the month when the Quran was revealed to the Prophet Mohammed.
Fasting during the holy month is one of the Five Pillars of Islam and is mandatory for all Muslims who are in good health.
Those exempt include young children, anyone who is sick, travellers and women who are pregnant, nursing or menstruating.
Ramadan is also considered a nocturnal month for Muslims who end their daily fast at sunset, then begin longer-form Taraweeh prayers that are traditionally followed by social gatherings that last into the night.
Moon-sighting significance
The sighting of the Moon signifies the start and the end of Ramadan, the ninth month of the Islamic calendar.
Religious authorities in the Middle East and beyond will soon begin scanning the night sky for the first glimpse of a crescent Moon.
In the Islamic lunar calendar, Ramadan is preceded by the month of Shabaan.
The month of fasting and spirituality begins when Moon-sighting committees convene after sunset on Shabaan 29 to look for a crescent Moon, in a tradition that has lasted thousands of years.
The crescent Moon is an important symbol in Islam and is used in Ramadan decorations.
It can often be seen hung outside homes, on Ramadan lanterns and even on gift-wrapped chocolates, dates and sweets exchanged by family, friends and neighbours.
Ramadan preparations around the world: in pictures
