A giant new clock being built in the Islamic holy city of Mecca hopes to usurp the role of Greenwich Observatory, and aims to have the world's 1.5 billion Muslims setting their watches by its time.
The four-faced clock, which bears a striking resemblance to Big Ben's tower, will top a massive skyscraper that when completed will stand at almost 2,000 feet, making it one of the world's tallest buildings.
Only one of the clock's four faces has so far been completed and is covered with 98 million pieces of glass mosaics. Each face will be inscribed with 'God is greatest' in Arabic and fitted with thousands of coloured lights, making it visible from more than 16 miles.
It will run on Arabia Standard Time, which is three hours ahead of GMT, and will begin testing tomorrow.
The Saudi clock, will dwarf St Stephen's Tower which houses Big Ben, once the largest four-faced clock in the world, with dials more than five times greater in area.
Islamic scholars hope that when the timepiece is finished, it will eclipse Greenwich Observatory as the world's centre of time.
'Putting Mecca time in the face of Greenwich Mean Time, this is the goal,' said Mohammed Al-Arkubi, the manager of one of the hotels in the complex.
At a conference in Doha in 2008, Muslim clerics and scholars presented 'scientific' arguments that Mecca time is the true global meridian. They said that Mecca is the centre of the world and that the Greenwich standard was imposed by the West.
Greenwich was chosen as the starting point for the measurement of time at the International Meridian Conference in 1884 and has retained its crown largely unchallenged during the ensuing 125 years.
The 130 foot diameter clock dials in Mecca will also bigger than the current world record holder at the Cevahir Mall clock in Istanbul, which has a 36 meter face.
The complex overlooks Mecca's famed Grand Mosque, which Muslims worldwide face during their five daily prayers and is part of Saudi efforts to develop the city visited by millions of pilgrims every year.
German and Swiss engineers designed the clock and according to the Ministry of Religious Endowments, the entire project will cost $800 million.