The crescent moon has NOT been sighted in Saudi Arabia. Subsequently, Ramadan will commence on the night of Wednesday, the first day of fasting on Thursday, in shā Allāh.
Ramadan, also known as Ramazan or Ramzan or Ramzaan, may begin in India, Pakistan, Bangladesh and other South Asian countries a day later i.e. from the evening of March 23 or 24, Ramadan 1444 AH when the first fast will be observed depending upon the sighting of the crescent moon.
The fasting date changes yearly because the Islamic calendar is based on the lunar cycle hence, its starting and end date depends upon the sighting of the crescent moon.
Usually, the crescent of Ramadan is first sighted in Saudi Arabia and some parts of India along with some Western countries and then usually a day later in the rest of India, Pakistan, Bangladesh and other countries.