The crescent moon, which signifies the start of the holy month of Ramadan, was not visible in Saudi Arabia on Tuesday night, as a result of which Sha'ban will end on Wednesday and Ramadan will start on Thursday.
To authenticate the moon sighting, the Kingdom's moon-sighting committee will convene once more on Wednesday night.
Muslims follow a lunar calendar with 12 months and 354 or 355 days per year. Sighting a crescent moon heralds the start of Ramadan, the ninth month of the Islamic calendar.
The starting date of the dawn-dusk fasting month is determined by both lunar calculations and physical sightings of a new moon.
Fasting during Ramadan is one of the five pillars of Islam and is mandatory for all healthy Muslims.