UTC Offset Lookup

In short An offset is a property of a moment in a place, never a property of the place by itself, so the list of zones sitting on any given offset is different in six months. This page filters your browser's own zone list against the offset in force right now and tells you how many of the results change their clocks during the year — which is how many will drop off the list later. Three facts about offsets are worth carrying around. Every offset in use is a whole number of quarter hours from UTC: half-hour offsets are ordinary, used by India, Iran, Afghanistan, Myanmar and Newfoundland among others, and three places use forty-five minutes — Nepal at UTC+05:45, Eucla in Western Australia at UTC+08:45 and the Chatham Islands at UTC+12:45. Any code that stores an offset as a whole number of hours is wrong for well over a billion people. Second, the world spans twenty-five hours, not twenty-four, running from UTC−11:00 to UTC+14:00, which is why there are moments when three different calendar dates are in progress somewhere on earth simultaneously. Third, the zone identifiers your browser lists may use historical city names — ICU keeps older identifiers as canonical, so a list can show Asia/Calcutta while Asia/Kolkata is what anyone would type. Both work and resolve to the same zone.