How to Use the World Clock
This world clock auto-detects your browser's time zone on load and sets it as the main clock. If detection fails, it defaults to India Standard Time (IST, UTC+05:30).
Country Strip
The scrollable strip at the top shows 13 popular time zones with live times. Click any pill to instantly switch the main clock to that country.
World Clocks (up to 5)
Click any empty slot to add a country clock. Each card shows the country's flag, live time, date, and hour difference from your main clock. Click a filled card to change it; use the ✕ button to remove it.
Time Zone Comparison Timeline
The comparison section shows a 48-hour timeline for each selected country. The highlighted column is the current hour. Drag any timeline row left or right to scroll all rows together — letting you find overlap windows for meetings and calls across time zones.
Time zone offset = local time - UTC time
IST (India) = UTC +05:30
JST (Japan) = UTC +09:00
EST (New York) = UTC -05:00 (UTC -04:00 DST)
PST (Los Angeles) = UTC -08:00 (UTC -07:00 DST)
BST (London) = UTC +01:00 (summer)
GST (Dubai) = UTC +04:00 (no DST)
Frequently Asked Questions
What is DST (Daylight Saving Time)?
Daylight Saving Time (DST) is the practice of advancing clocks by one hour during summer months to extend evening daylight. Countries like the USA, UK, and EU members observe DST; India, Japan, China, and UAE do not. This calculator uses your browser's built-in timezone data (Intl API) which automatically accounts for current DST status.
Why does the time zone offset sometimes include 30 or 45 minutes?
Most time zones are offset in full hours from UTC, but some countries use non-standard offsets. India uses UTC+05:30 (half-hour offset). Nepal uses UTC+05:45 (45-minute offset). Iran uses UTC+03:30. These non-standard offsets are historical in origin, often set to align with geographic longitude more precisely.
How do I find a good meeting time between India and the USA?
India (IST, UTC+05:30) is 10.5 hours ahead of New York (EST, UTC-05:00) in winter, or 9.5 hours in summer when the US observes EDT. The best overlap window is 6:30–8:30 PM IST = 8:00–10:00 AM EST. Use the comparison timeline on this page: add India and New York, then drag until work-hour cells (lighter background) overlap on both rows.
