"The four faces of the Mecca Clock are illuminated by 2 million LED lights. "In the name of Allah". The Mecca Clock will display, of course, Arabia Standard Time (three hours ahead of GMT). The clock faces are 151 feet in diameter, which dwarfs the face of Big Ben (23 feet in diameter) considerably. The Big Ben clock was installed in 1859 to replace the Palace of Westminster's which had been destroyed by fire in 1834."
http://revelationawaitsanappointedtime.blogspot.com/2010/08/blog-post.html