Time Zone Converter
Convert time between time zones around the world. Enter a time, select the source and target time zones, and see the converted time instantly.
Time Zone Reference
The world is divided into 24 standard time zones, each roughly 15 degrees of longitude wide. Time zones are expressed as offsets from UTC (Coordinated Universal Time). In practice, time zone boundaries follow political and geographic borders rather than strict meridian lines, resulting in over 30 distinct time zone offsets worldwide, including half-hour and quarter-hour variations.
Conversion Formula
Target Time = Source Time + (Target UTC Offset - Source UTC Offset). For example, to convert 3:00 PM EST (UTC-5) to CET (UTC+1): 3:00 PM + (1 - (-5)) = 3:00 PM + 6 = 9:00 PM CET. If the result exceeds 24:00, subtract 24 and advance one day. If it is negative, add 24 and go back one day.
US Time Zones
- EST/EDT (Eastern): UTC-5 / UTC-4 — New York, Miami, Atlanta, Washington D.C., Boston
- CST/CDT (Central): UTC-6 / UTC-5 — Chicago, Dallas, Houston, Nashville, New Orleans
- MST/MDT (Mountain): UTC-7 / UTC-6 — Denver, Phoenix (no DST in AZ), Salt Lake City
- PST/PDT (Pacific): UTC-8 / UTC-7 — Los Angeles, Seattle, San Francisco, Portland
- AKST/AKDT (Alaska): UTC-9 / UTC-8 — Anchorage, Fairbanks, Juneau
- HST (Hawaii): UTC-10 (no DST) — Honolulu
International Time Zones
- GMT/UTC+0: London (winter), Lisbon, Accra
- CET/CEST: UTC+1 / UTC+2 — Paris, Berlin, Rome, Madrid, Warsaw
- EET/EEST: UTC+2 / UTC+3 — Athens, Helsinki, Cairo, Bucharest
- MSK: UTC+3 — Moscow, Istanbul, Riyadh
- IST: UTC+5:30 — Mumbai, New Delhi, Bangalore (India)
- CST (China): UTC+8 — Beijing, Shanghai, Singapore, Hong Kong, Taipei
- JST: UTC+9 — Tokyo, Osaka
- KST: UTC+9 — Seoul, Busan
- AEST/AEDT: UTC+10 / UTC+11 — Sydney, Melbourne, Brisbane
- NZST/NZDT: UTC+12 / UTC+13 — Auckland, Wellington
Common Business Hours Overlap
For international business calls, finding overlapping work hours is essential. US East Coast (EST) and UK (GMT) overlap from 9:00 AM - 12:00 PM EST (2:00 PM - 5:00 PM GMT). US West Coast (PST) and East Asia (JST/KST) have very limited overlap, with 5:00 PM - 7:00 PM PST matching 10:00 AM - 12:00 PM the next day in Tokyo/Seoul.
Daylight Saving Time (DST)
In the US, DST begins on the second Sunday in March (clocks spring forward 1 hour) and ends on the first Sunday in November (clocks fall back 1 hour). In Europe, DST runs from the last Sunday in March to the last Sunday in October. During the brief windows when the US and Europe switch on different dates, time differences temporarily shift by one hour. Always verify current offsets during March/April and October/November transitions.