Time Zone Converter

Time zones divide the Earth into regions, each observing a standard offset from Coordinated Universal Time (UTC). Converting between zones adjusts the clock time by the difference in offsets while preserving the same absolute moment. UTC−5 (U.S. Eastern Standard Time) is 5 hours behind UTC; UTC+9 (Japan Standard Time) is 9 hours ahead. The offset difference between EST and JST is 14 hours.

Concrete example: a meeting at 2:00 PM Eastern Time (ET) on June 11, 2026. In summer, Eastern observes EDT (UTC−4). Japan uses JST (UTC+9) year-round with no daylight saving. The offset difference is 13 hours. 2:00 PM EDT + 13 hours = 3:00 AM JST on June 12 — the date advances because Japan is ahead. London in summer (BST, UTC+1): 2:00 PM EDT = 7:00 PM BST, same calendar day.

Daylight saving time (DST) complicates offsets. U.S. clocks spring forward one hour on the second Sunday in March and fall back on the first Sunday in November. European DST runs from the last Sunday in March to the last Sunday in October — not aligned with U.S. dates. For two weeks each spring and autumn, the U.S.–Europe offset differs from the rest of the year. Always use zone abbreviations with dates, not fixed offsets, for future scheduling.

UTC (or GMT) serves as the universal reference for aviation, computing, and science. Zulu time (Z) is identical to UTC. When converting, the reliable method converts source time to UTC first, then to the target zone. This two-step approach avoids DST edge cases that break fixed-offset shortcuts.

Select a source time zone, date, and time, then choose the target zone. The calculator shows the equivalent local time in the destination zone, flags date changes, and accounts for daylight saving rules. Essential for international calls, flight arrivals, broadcast scheduling, and remote team coordination.