Time Difference Calculator: How to Compare Any Two Cities
Need to know the time difference between two cities? Whether you're scheduling a meeting, planning a call, or just figuring out if your friend is awake on the other side of the world, our guide will help you calculate time differences instantly.
Popular Time Differences
Here are the most commonly searched city pairs. Click any to see detailed time info:
🇺🇸 New York → 🇬🇧 London 5h
🇺🇸 New York → 🇯🇵 Tokyo 14h
🇺🇸 New York → 🇦🇺 Sydney 16h
🇬🇧 London → 🇯🇵 Tokyo 9h
🇬🇧 London → 🇦🇪 Dubai 4h
🇺🇸 LA → 🇬🇧 London 8h
🇺🇸 LA → 🇯🇵 Tokyo 17h
🇦🇺 Sydney → 🇬🇧 London 11h
🇦🇪 Dubai → 🇺🇸 New York 9h
🇸🇬 Singapore → 🇬🇧 London 7-8h
🇮🇳 Mumbai → 🇺🇸 New York 10.5h
🇨🇳 Beijing → 🇺🇸 New York 13h
How to Calculate Time Differences
- Find each city's UTC offset — For example, New York is UTC-5 (EST) and Tokyo is UTC+9 (JST)
- Subtract the offsets — 9 - (-5) = 14 hours difference
- Check for DST — During summer, New York becomes UTC-4, making it 13 hours
- Use our tool — We do all this automatically at worldtimessync.com
The Trickiest Time Differences
Some time differences are confusing because of DST transitions that happen at different dates in different countries:
- New York ↔ London: Usually 5h, but can be 4h or 6h during DST transition weeks in March and October
- New York ↔ Sydney: Usually 15-16h, but flips because US and Australia have opposite DST seasons
- London ↔ New York: The "5 hours ahead" rule changes to 4h for about 2 weeks per year
- India ↔ anywhere: India (UTC+5:30) has a half-hour offset, making calculations less intuitive
Time Differences for Business
If you work with international teams, here are the best overlapping business hours:
- New York ↔ London: 9-11 AM EST = 2-4 PM GMT (3 hour overlap)
- New York ↔ India: 7-9 AM EST = 5:30-7:30 PM IST (limited overlap)
- London ↔ Singapore: 8-10 AM GMT = 4-6 PM SGT (2 hour overlap)
- San Francisco ↔ Tokyo: 5-7 PM PST = 9-11 AM JST next day
Use our meeting planner to find the perfect time across multiple time zones.