Moon sighters in Saudi Arabia and other Muslim-majority countries were unable to sight the moon last night and have thus announced that Shaban, the last lunar month before Ramadan, will start on Thursday evening.
So far Algeria, Egypt, Jordan, Palestine, Libya, Tunisia, Syria have officially confirmed the same.
The Muslim holy month of Ramadan will begin either on Saturday, May 27 or on Sunday, May 28, depending on moon sighting on the eve of May 27.
Muslim lunar months last between 29 and 30 days, depending on sighting of the moon on the 29th night of each month. If the moon is not visible the month will last 30 days.
By the Gregorian solar calendar, Ramadan comes 11 to 12 days earlier each year. Last year, the first day of Ramadan was on June 6, 2016.