Why do offsets change during the year?
Daylight saving. New York moves between UTC−5 and UTC−4, and the US and Europe switch on different dates, creating one- to two-week windows where the usual gap is off by an hour.
Convert time between any time zones instantly. See the current time in multiple cities and calculate time differences for meetings and travel.
Target time = source time + (target UTC offset − source UTC offset), adjusted for daylight saving in each zone.
9:00 am in New York (UTC−4 in summer) is 2:00 pm in London (UTC+1) and 6:30 pm in Mumbai (UTC+5:30) — a five-hour and nine-and-a-half-hour shift respectively.
Daylight saving. New York moves between UTC−5 and UTC−4, and the US and Europe switch on different dates, creating one- to two-week windows where the usual gap is off by an hour.
India (UTC+5:30), Nepal (UTC+5:45), parts of Australia (UTC+9:30) and Newfoundland (UTC−3:30) use half- or quarter-hour offsets.
Agree everything in UTC and let each participant convert, and prefer 13:00–16:00 UTC, which is the widest overlap for the Americas, Europe and Asia.