Time Zone Converter

Coordinating a meeting across three time zones, booking a flight that crosses regions, or catching an international colleague during their working hours all hinge on one thing: knowing the exact offset between two clocks. This converter translates a time among the six US time zones, UTC and GMT, and three zones abroad (Central European, Japan, and Australia Eastern) in a single step. A wrong guess about the hour difference is the difference between making a connection and missing it.

Each zone in the list carries a fixed standard-time offset from Coordinated Universal Time (UTC): Eastern −5, Central −6, Mountain −7, Pacific −8, Alaska −9, Hawaii −10, UTC and GMT 0, Central European +1, Japan +9, and Australia Eastern +10. The converter takes the difference between the target and source offsets, adds it to the time you enter, and flags a result that lands on the next or previous day. It does not ask for a date and does not apply daylight saving time, as the note under the result says.

DST is where most conversions go wrong, so adjust for it yourself. US clocks go forward one hour at 2:00 AM on the second Sunday of March and back on the first Sunday of November (15 U.S.C. 260a); Arizona and Hawaii stay on standard time. Between two US zones that both observe DST the gap does not change, so Eastern to Pacific is 3 hours all year. Against UTC or Japan, which have no DST, a US zone is an hour closer from March to November (New York is UTC−4 in summer, not −5). Against the UK, which changes its clocks on the last Sundays of March and October, the gap matches the converter for most of the year but is 4 hours instead of 5 during the weeks when only one side has switched. Watch the abbreviations too: EST and EDT are an hour apart.