Timezone Converter
Convert times between different time zones.
Understanding Time Zones
A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions instead of strictly following longitude lines, because it is convenient for areas in close commercial or other communication to keep the same time.
What is UTC?
Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time. It is not adjusted for daylight saving time and serves as the basis for civil time around the world. UTC replaced Greenwich Mean Time (GMT) as the international time standard in 1972.
Key Facts About UTC:
- Based on atomic time, extremely precise
- Not affected by daylight saving time
- Used as the reference point for all time zones
- Abbreviated as UTC (not CUT) as a compromise between English and French
- Located along the Prime Meridian (0° longitude)
How Time Zones Work
The world is divided into 24 time zones, each representing one hour of the day. Time zones are measured as offsets from UTC, ranging from UTC-12 to UTC+14.
Time Zone Notation
- UTC+5: 5 hours ahead of UTC
- UTC-8: 8 hours behind UTC
- UTC+0: Same as UTC (London, UK during winter)
Daylight Saving Time (DST)
Daylight Saving Time is the practice of moving clocks forward by one hour during warmer months so that darkness falls at a later clock time. The rationale is to make better use of daylight.
DST Around the World
| Region | DST Practice | Time Change |
|---|---|---|
| United States | Observed (most states) | 2nd Sunday in March / 1st Sunday in November |
| European Union | Observed | Last Sunday in March / Last Sunday in October |
| Australia | Varies by state | 1st Sunday in October / 1st Sunday in April |
| Arizona (US) | Not observed | N/A |
| Japan | Not observed | N/A |
| China | Not observed | N/A |
Major Time Zones
North America
| Time Zone | UTC Offset (Standard) | Major Cities |
|---|---|---|
| Eastern (ET) | UTC-5 | New York, Miami, Toronto |
| Central (CT) | UTC-6 | Chicago, Dallas, Mexico City |
| Mountain (MT) | UTC-7 | Denver, Phoenix, Calgary |
| Pacific (PT) | UTC-8 | Los Angeles, Seattle, Vancouver |
Europe and Africa
| Time Zone | UTC Offset | Major Cities |
|---|---|---|
| Greenwich Mean Time | UTC+0 | London, Lisbon, Dublin |
| Central European Time | UTC+1 | Paris, Berlin, Rome |
| Eastern European Time | UTC+2 | Athens, Cairo, Helsinki |
Asia and Pacific
| Time Zone | UTC Offset | Major Cities |
|---|---|---|
| India Standard Time | UTC+5:30 | Mumbai, Delhi, Bangalore |
| China Standard Time | UTC+8 | Beijing, Shanghai, Hong Kong |
| Japan Standard Time | UTC+9 | Tokyo, Osaka, Kyoto |
| Australian Eastern Time | UTC+10 | Sydney, Melbourne, Brisbane |
Time Zone Oddities
Countries with Multiple Time Zones
- Russia: 11 time zones (most in the world for a single country)
- United States: 6 time zones (including Alaska and Hawaii)
- Canada: 6 time zones
- France: 12 time zones (including overseas territories)
Unusual Time Zones
- Nepal: UTC+5:45 (one of the few 45-minute offset zones)
- Newfoundland, Canada: UTC-3:30 (30-minute offset)
- Chatham Islands, New Zealand: UTC+12:45 (45-minute offset)
- China: Uses a single time zone despite spanning 5 geographical zones
- Kiribati: Spans UTC+12 to UTC+14, crosses the International Date Line
International Date Line
The International Date Line (IDL) is an imaginary line on Earth's surface located at approximately 180° longitude in the Pacific Ocean. When you cross the date line:
- Traveling west: You add one day (Monday becomes Tuesday)
- Traveling east: You subtract one day (Tuesday becomes Monday)
Fun Fact: Some Pacific islands near the date line have modified their time zones so that business partners on opposite sides don't operate on different days of the week.
Practical Uses of Time Zone Conversion
Business and Communication
- International meetings: Schedule video calls across time zones
- Customer support: Determine operating hours for global customers
- Stock trading: Know when international markets open/close
- Project coordination: Collaborate with teams in different countries
Travel Planning
- Flight arrivals: Calculate landing time in destination timezone
- Jet lag management: Prepare for time zone changes
- Hotel check-in: Ensure you arrive during business hours
- Event timing: Attend webinars, sports events at correct local time
Personal Connections
- Family abroad: Call relatives at convenient times
- Online gaming: Coordinate with international teammates
- Live events: Watch concerts, sports, broadcasts from other countries
Tips for Working Across Time Zones
Best Practices
- Use UTC for scheduling: Eliminates ambiguity in international teams
- State the time zone clearly: Always include timezone abbreviation (PST, EST, etc.)
- Consider daylight saving: Check if DST affects the date you're scheduling
- Use world clock apps: Keep multiple clocks visible on your devices
- Be mindful of working hours: Avoid scheduling calls outside 9-5 local time
Common Pitfalls to Avoid
- Forgetting about daylight saving time transitions
- Confusing AM and PM in 12-hour format
- Not accounting for date changes across the International Date Line
- Assuming all time zones are full-hour offsets
- Using ambiguous timezone abbreviations (CST can mean Central Standard Time, China Standard Time, or Cuba Standard Time)
Time Zone History
Before time zones were established, each city kept its own local time based on the sun's position. This created chaos for railways and telecommunications in the 19th century.
Key Historical Events
- 1884: International Meridian Conference establishes Greenwich as Prime Meridian
- 1883: U.S. and Canada adopt time zones for railroad schedules
- 1918: U.S. Congress passes the Standard Time Act
- 1972: UTC replaces GMT as the international time standard
- 2007: U.S. extends daylight saving time by 4 weeks
Did You Know?
Sir Sandford Fleming, a Canadian railway engineer, is credited with proposing the worldwide system of time zones in 1879. He was frustrated by missing a train due to a confusing timetable.
Quick Reference
Common Offsets from UTC:
- New York: UTC-5 (EST) / UTC-4 (EDT)
- London: UTC+0 (GMT) / UTC+1 (BST)
- Paris: UTC+1 (CET) / UTC+2 (CEST)
- Dubai: UTC+4
- India: UTC+5:30
- China: UTC+8
- Japan: UTC+9
- Sydney: UTC+10 / UTC+11 (DST)
Time Zone Abbreviations
- EST/EDT: Eastern Standard/Daylight Time
- CST/CDT: Central Standard/Daylight Time
- MST/MDT: Mountain Standard/Daylight Time
- PST/PDT: Pacific Standard/Daylight Time
- GMT: Greenwich Mean Time
- BST: British Summer Time
- CET: Central European Time
- IST: India Standard Time
- JST: Japan Standard Time