Converting time between zones
A time zone converter answers one question: “When it’s this time here, what time is it there?” Pick a date and time in one city, choose your destinations, and World on Time does the offset math — including the awkward cases, like half-hour zones (India is UTC+5:30) and regions that don’t observe daylight saving.
What UTC offsets actually mean
Every time zone is described as a distance from UTC (Coordinated Universal Time). New York in winter is UTC−5; London is UTC+0. The difference between two cities is just the difference between their offsets — but those offsets change during the year, which is where most mistakes happen.
Why a conversion can shift by an hour
Daylight saving time moves clocks forward in spring and back in autumn — but not everywhere, and not on the same dates. For a few weeks each year, the gap between, say, New York and London is one hour off its usual value because one has switched and the other hasn’t. This converter accounts for the exact transition dates, so you don’t get caught out. For the full story, see our guide on how daylight saving time works.
Frequently asked questions
What’s the difference between UTC and GMT?
For everyday purposes they’re the same reference point. UTC is the modern technical standard; GMT is the older term still used in casual and some regional contexts.
Why does the same city sometimes show two different offsets?
Because of daylight saving. A city can be UTC−8 in winter and UTC−7 in summer.
What happens during the changeover hour?
When clocks spring forward, an hour doesn’t exist; when they fall back, an hour repeats. The converter uses the official rules to resolve these correctly.