Time Zone Converter
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Convert a dated local time between city-based time zones, including the destination date and UTC-offset difference. Select the actual event date: daylight saving time (DST) can change the answer by an hour, and countries do not all move their clocks on the same weekend. The converter uses the rules available in your browser's time-zone database.
For the most common conversions there are dedicated pages with full 24-hour tables: EST to IST, PST to IST, CST to IST, BST to IST, GMT to IST and IST to EST.
Current time around the world
| Zone | Local time now | UTC offset |
|---|
How time zones convert
Target time = Source time − Source UTC offset + Target UTC offset
Every zone is defined by its offset from UTC. India is UTC+5:30 all year. New York is UTC−5 in winter (EST) and UTC−4 in summer (EDT). London is UTC+0 in winter (GMT) and UTC+1 in summer (BST). Because zones switch to daylight saving on different dates, the difference between two cities can change for a few weeks each spring and autumn. The converter looks up the offset for the exact date you enter.
Common differences from India (IST)
| Zone | January 15, 2026 | July 15, 2026 |
|---|---|---|
| New York (EST/EDT) | IST is 10:30 ahead | IST is 9:30 ahead |
| Chicago (CST/CDT) | 11:30 ahead | 10:30 ahead |
| Los Angeles (PST/PDT) | 13:30 ahead | 12:30 ahead |
| London (GMT/BST) | 5:30 ahead | 4:30 ahead |
| Berlin, Paris (CET/CEST) | 4:30 ahead | 3:30 ahead |
| Dubai (GST) | 1:30 ahead | 1:30 ahead |
| Singapore (SGT) | 2:30 behind | 2:30 behind |
| Sydney (AEST/AEDT) | 5:30 behind (AEDT) | 4:30 behind (AEST) |
These January and July examples are not valid for every date. Sydney is in the southern hemisphere: its daylight-saving season falls in different months from New York or London. Use the event date for transition-week calculations.
Scheduling across zones
For a call between India and New York, 9 AM to 11 AM in New York is 6:30 PM to 8:30 PM in India during EDT, or 7:30 PM to 9:30 PM during EST. For India and London, 2 PM to 6 PM IST matches 9:30 AM to 1:30 PM in London during BST. Include the date and both local times in the invitation; an evening on one side can be the next morning on the other.
Abbreviations are ambiguous: CST is used for US Central, China and Cuba, and IST for India, Israel and Ireland. The converter uses city-based IANA zones to avoid that problem.
What happens when clocks go forward or back?
A spring-forward change can skip a local time; a fall-back change can make the same clock time occur twice. If an event is in a repeated hour, confirm the intended UTC offset with its organiser rather than relying on a clock reading alone. Check each recurring meeting around clock changes, since its time in another city may move even when the original local time stays fixed.
Read the IANA time-zone data explanation and NIST daylight-saving guide. Keep your browser updated; future rules can change by government decision.
Use a date, not just an abbreviation
At 09:00 in New York on 15 January 2026, it is 19:30 in Kolkata. At 09:00 on 15 July 2026, it is 18:30 in Kolkata. New York changes its offset; Kolkata does not. EST strictly means UTC−5, while the New York city selection follows EST or EDT according to the date. Future rules can change.
Frequently asked questions
How do I convert EST to IST?
Add 10 hours 30 minutes when New York is on standard time (November to March) or 9 hours 30 minutes during daylight time (March to November). 9 AM EST is 7:30 PM IST. The EST to IST page has the full table.
Why did the time difference change by an hour?
One of the selected cities may have started or ended daylight saving time. New York, London and Sydney change clocks under current rules; Kolkata, Singapore, Dubai and Phoenix do not. Rules vary within countries too. Changes need not happen on the same dates, so check the actual meeting date rather than a generic summer or winter difference.
What is the difference between GMT and UTC?
For everyday purposes they are the same: both are the zero offset. UTC is the technical standard. GMT is the name of London's winter time zone. In summer London moves to BST (UTC+1), so "GMT" and "London time" are not always the same.
Does the converter work for past and future dates?
It uses the historical and future rules available in your browser's time-zone database. Old browsers can have old data, and future rules can change. Check important dates against an official local source and clarify any repeated local hour with the organiser.
Related calculators and tools
- EST to IST ConverterPlan calls from New York to India using the event date, daylight-saving offsets and day changes.
- PST to IST ConverterPlan calls from Los Angeles to India using the event date, daylight-saving offsets and day changes.
- BST to IST ConverterPlan calls from London to India using the event date, daylight-saving offsets and day changes.
- Basic CalculatorEveryday arithmetic with keyboard input and history.
Conversions use the IANA time zone database in your browser. Future daylight saving rules can change by government decision, so check official sources for dates far in the future.