Time Zone Converter
Convert time between major world time zones including UTC, EST, PST, GMT, CET, JST, IST, and AEST.
Enter any time to see equivalents across all selected zones.
Time zone conversion is essential for international communication, remote team scheduling, travel planning, and business operations. The world is divided into 24 primary time zones (plus numerous fractional offsets), all measured as positive or negative offsets from UTC (Coordinated Universal Time).
Formula: Target Time = Source Time + (Target UTC Offset − Source UTC Offset) Or: Target Time = UTC Time + Target UTC Offset Meeting UTC time = Local Time − Local UTC Offset
Key UTC offsets for major cities:
| City | Standard Time | DST |
|---|---|---|
| London, UK | UTC+0 | UTC+1 |
| Paris, Berlin | UTC+1 | UTC+2 |
| Dubai, UAE | UTC+3 | No DST |
| Mumbai, India | UTC+5:30 | No DST |
| Singapore | UTC+8 | No DST |
| Tokyo, Japan | UTC+9 | No DST |
| Sydney, Australia | UTC+10 | UTC+11 |
| New York, USA | UTC−5 | UTC−4 |
| Chicago, USA | UTC−6 | UTC−5 |
| Denver, USA | UTC−7 | UTC−6 |
| Los Angeles, USA | UTC−8 | UTC−7 |
| São Paulo, Brazil | UTC−3 | UTC−2 |
Daylight Saving Time (DST) complicates conversions:
- US DST: Second Sunday in March → First Sunday in November
- EU DST: Last Sunday in March → Last Sunday in October
- Australia DST: First Sunday in October → First Sunday in April (Southern Hemisphere — opposite seasons)
- Many countries do NOT observe DST: Japan, China, India, UAE, most of Africa
Worked example — scheduling a call: New York (UTC−4 in summer/DST) wants to schedule a call with colleagues in:
- London (UTC+1): Offset difference = +1−(−4) = +5 hours
- Dubai (UTC+3): Difference = +3−(−4) = +7 hours
- Tokyo (UTC+9): Difference = +9−(−4) = +13 hours
If New York proposes 9:00 AM EDT:
- London = 9:00 AM + 5h = 2:00 PM BST ✓
- Dubai = 9:00 AM + 7h = 4:00 PM GST ✓
- Tokyo = 9:00 AM + 13h = 10:00 PM JST ✗ (too late)
Best compromise: 8:00 AM New York → Tokyo 9:00 PM (borderline acceptable for urgent calls).
Tools to verify: The IANA timezone database (used by all operating systems) is the authoritative source. World Time Buddy and timeanddate.com are helpful planning resources.