Timezone Converter: How to Convert Times Across Time Zones
How Time Zones Work
Time zones divide the world into regions that observe the same standard time. Ideally, each time zone is a 15° longitude band (24 bands × 15° = 360°), offset by one hour. In practice, time zone boundaries follow political and geographic borders, creating irregular shapes and offsets that include 30-minute and 45-minute increments.
There are 38 distinct UTC offsets in current use, ranging from UTC-12 (Baker Island) to UTC+14 (Line Islands in Kiribati). The same calendar day exists simultaneously in different years for a few minutes around the International Date Line.
UTC and Offsets
UTC (Coordinated Universal Time) is the global time standard — the reference from which all time zones are offset. UTC has no daylight saving time adjustment and doesn't change. UTC+5:30, for example, is 5 hours and 30 minutes ahead of UTC (used in India).
Important UTC offsets:
- UTC-8 (PST / US Pacific Standard Time)
- UTC-5 (EST / US Eastern Standard Time)
- UTC+0 (GMT / UK Winter Time)
- UTC+1 (CET / Central European Time)
- UTC+5:30 (IST / India Standard Time)
- UTC+8 (CST / China Standard Time)
- UTC+9 (JST / Japan Standard Time)
Daylight Saving Time
Daylight Saving Time (DST) advances clocks by one hour during summer months, shifting UTC offsets. For example, US Eastern Time is UTC-5 (EST) in winter and UTC-4 (EDT) in summer. DST starts and ends on different dates in different countries, which means the difference between US and European times changes twice a year.
Beware of DST transitions: The US and Europe switch DST on different dates (US: second Sunday in March, EU: last Sunday in March). For the 2–3 weeks between US and EU transitions, the offset between New York and London changes from 5 hours to 4 hours.
Countries that don't observe DST include China, Japan, India, most of Africa, and Arizona (US). Australia observes DST in the southern hemisphere summer (October–April).
Using the Converter
Type the time you want to convert, including AM/PM or use 24-hour format. Include the date — DST status changes the offset, so the date matters.
Choose the time zone the input time is in. The tool includes full IANA time zone names (America/New_York, Europe/London, Asia/Tokyo) as well as common abbreviations.
Add one or more target time zones. The tool shows the equivalent time in each zone simultaneously.
Each result shows the converted time and date, the UTC offset for that date (accounting for DST), and the UTC equivalent.
Scheduling Across Time Zones
Finding a meeting time that works across multiple time zones is one of the most common use cases. Overlapping business hours:
- New York + London: 9am–1pm ET (2pm–6pm GMT)
- New York + Paris: 9am–noon ET (3pm–6pm CET)
- New York + Singapore: No overlap in standard business hours — 8pm–9am ET corresponds to 8am–9pm SGT
- London + Tokyo: No good overlap — any time in London business hours is early morning or evening in Tokyo
Tips for Global Teams
- Always share times in UTC for unambiguous scheduling — write "3pm UTC" not "3pm GMT" (they're often the same but not always, and GMT is ambiguous).
- Use calendar tools for recurring meetings — tools like Google Calendar and Outlook handle DST transitions automatically when you share events across time zones.
- Be specific about abbreviations — CST can mean US Central Standard Time (UTC-6), China Standard Time (UTC+8), or Cuba Standard Time (UTC-5). Always use the full IANA name or explicit UTC offset.
- Rotate meeting times for globally distributed teams — don't always make the same region take early mornings or late evenings.