The United Kingdom operates on Greenwich Mean Time (GMT) during winter months, which is Coordinated Universal Time (UTC+0). During daylight saving time, observed from the last Sunday in March to the last Sunday in October, the UK switches to British Summer Time (BST), which is UTC+1.
All of the United Kingdom follows the same timezone, including England, Scotland, Wales, and Northern Ireland. Major cities like London, Manchester, Birmingham, Edinburgh, Cardiff, and Belfast all observe the same time.
Greenwich Mean Time is named after the Royal Observatory in Greenwich, London, which has been the reference point for world timekeeping since 1884. The Prime Meridian (0° longitude) passes through Greenwich, making London the literal center of world time.