Mecca Time was a proposed time standard that uses the line of longitude that goes through Mecca, Saudi Arabia (39°49′34″ E of the Greenwich Meridian) as its Prime Meridian. A clock based on this meridian would be at approximately UTC+02:39:18.3.
On 11 August 2010, (1 Ramadan, AH 1431), the world's largest clock (at Mecca) started to operate. Some Muslims hoped that this would establish "Mecca Time" as the world's defining timezone. While officials had originally expressed the conviction that the clock might help to establish Mecca as a prime meridian, it was set to Arabia Standard Time, a time zone based on Coordinated Universal Time and thus in coordination with mean solar time at the IERS Reference Meridian.
The "Mecca: the Center of the Earth, Theory and Practice" conference was organized and attended by Muslim theologians and other religious officials from across the world. The Qatar meeting was the culmination of efforts to seek answers for scientific questions from the Qur'an and other Islamic scriptures — a trend called "Ijaz al-Qur'an" (Miraculous nature of the Qur'an). The conference promotes the belief that Islamic scripture also revealed scientific details, which Islamic scholars seeking to unearth and publicize the textual evidence.
The conference revived a decades-old controversial issue, contending that the Greenwich Meridian was imposed by the United Kingdom and Western civilization during the colonial period and that Islam, unlike other religions, does not contradict science. One of the contentions was that unlike other longitudes, Mecca was in perfect alignment with the magnetic north. Muslim clerics hail this as evidence of the greatness of the qibla—the direction determined to be towards Mecca that Muslims across the world must turn towards while reciting prayers.
Mecca, however, is not actually aligned with the North Magnetic Pole. As the geomagnetic field of the earth continuously changes the deviation of the compass needle from true north (known as the magnetic declination) also slowly changes. In the past there were epochs when the compass needle at Mecca pointed true north (and there will be future epochs when this is true again) but at the moment the line of no compass deviation is located somewhat to the southeast of Mecca. In 2015 the (predicted) magnetic declination of Mecca is 3.3° East and will continue to increase at about +0.06° per year.
The opponents say that the center of the land hemisphere is located in France, near the city of Nantes (about 4700 km from Mecca). Others argue that Nantes is just the mean of land hemisphere, which is just the land mass on the earth excluding the water hemisphere, not the whole globe.
During the 1884 International Meridian Conference, when Greenwich was established as the initial meridian, the Ottoman Empire, at that time controlling Mecca, voted with the majority for Greenwich.
Pan-Arab satellite television networks, particularly Al Arabiya and Al Jazeera, refer to Saudi Arabia Time as "توقيت مكة المكرمة" (Tawqīt Makkah al-Mukarramah), i.e. "Mecca Time". Mecca Time is 3 hours ahead from Coordinated Universal Time, which is exactly the same as Arabia Standard Time, Moscow Time, Further-eastern European Time, East Africa Time, as well as Eastern European Summer Time during the summer.
- Abdelhadi, Magdi (April 21, 2008). "Muslim call to adopt Mecca time". BBC News.
- Blomfield, Adrian; Beckford, Martin (August 11, 2010). "Giant Mecca clock seeks to call time on Greenwich". The Telegraph.
- "Report: Muslim Leaders Want Mecca to Be Center of World Time Zones". FOX News. April 21, 2008.
- NOAA magnetic declination calculator