What is the name of the time zone used in the UK during winter?

The time zone used in the UK during winter is Greenwich Mean Time, commonly abbreviated GMT. GMT corresponds to UTC+00:00, so the UK’s winter clocks align with Coordinated Universal Time.

The name comes from the Royal Observatory at Greenwich in London, where the prime meridian—0 degrees longitude—was established. GMT became a major reference for international timekeeping during the nineteenth century, especially as railways, telegraph networks and global shipping needed a common standard.

During the summer, the UK advances its clocks by one hour to British Summer Time, or BST, which is UTC+01:00. This seasonal change is why “UK time” is not always the same as GMT. A frequent mistake is to call BST the UK’s standard winter time; BST is specifically the summer designation.

GMT and UTC are extremely close for everyday clock-reading, although UTC is the modern atomic-time standard. In ordinary trivia and civil-time contexts, GMT is the canonical name for the UK’s winter time.