Forget the clash of civilizations -- the next grand battle between East and West will be over Time itself. The world's largest clock is currently under construction in the Islamic holy city of Mecca, with the goal of moving Greenwich Mean Time to the Saudi Arabian city. The clock will tick off its first seconds tomorrow, one day after the beginning of Ramadan.

The clock itself bears a resemblance to Big Ben -- if Ben was on steroids. Its four faces, each 151 feet in diameter, will be lit with two million LED lights. It will sit on top of a tower that stretches 1,983 feet in the air. By comparison, Big Ben's faces are merely 23 feet in diameter, and its tower is only 316 feet tall. The tower also has some Islamic touches that are all its own: Arabic script reading "In the Name of Allah" runs below the clock faces, and white and green lights will flash during at the top of the clock will flash to signal the five daily times for prayer in Islam.

Greenwich has performed its job as international timekeeper admirably since 1884, so many people are going to be hard-pressed to think of a reason to change the Prime Meridian now. But at least one nation is starting to think that it's time for a change.