AST Arabia to GMT

Offset: AST is 3 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: Saudi Arabia

Principal Cities: The largest city in the AST time zone is Riyadh in Saudi Arabia, with about 4.206 million people. Other major cities in this time zone include Jeddah, Mecca, Medina, Sultanah.

Daylight Saving: Clocks in Arabia Standard Time (AST) do not change for daylight saving time, so AST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo

Principal Cities: The largest city in the GMT time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Abidjan, Dakar, Grand Dakar, Accra.

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.