Saudi Arabian moon observers said there was no sight of the Ramadan crescent on Tuesday, meaning millions of Muslims around the world will begin the holy month on Thursday.
According to reports on Saudi Arabian state TV, as published by Arab News, bad weather made observation of the crescent difficult.
The Kingdom and other Muslim nations like Indonesia declared Ramadan would not begin on Wednesday based on the observations by moon-sighting committees.
In Nigeria, the Sultan of Sokoto, Saad Abubakar, has advised Muslims to look out for the crescent moon on Wednesday, an indication the fasting will also start on Thursday.
Muslims around the world are set to mark the month, during which believers abstain from eating, drinking and smoking from dawn until sunset.
Fasting is intended to bring Muslims closer to God and remind them of those less fortunate.
The Islamic world follows a lunar calendar, and the traditional moon-sighting methodology can lead to different countries declaring the start of Ramadan a day or two apart
This year, Ramadan falls on long summer days for Muslims in the Northern Hemisphere.
Fasting during Ramadan is one of the five obligatory pillars of Islam, along with the Muslim declaration of faith, daily prayer, annual charity -- known as "zakat" -- and performing the Hajj pilgrimage in Makkah.