What UTC and GMT Really Mean (And Why UTC is Not a Time Zone)
Understanding the difference between the astronomical British timezone and the atomic Coordinated Universal Time.
While people frequently use UTC and GMT interchangeably, they are technically distinct. Greenwich Mean Time (GMT) is a civil time zone used in parts of the UK and Africa. During the summer, the UK observes British Summer Time (BST, UTC+1), meaning London is no longer on GMT.
Coordinated Universal Time (UTC), conversely, is not a timezone—it is an atomic time standard maintained by the Bureau International des Poids et Mesures (BIPM). UTC never undergoes daylight saving changes and never shifts. It is the zero reference against which all international time zones calculate offsets.
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