Time Zone Converter
Convert any time between world time zones — no API, no signup, works offline.
Converted Time
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Time Difference
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Live World Clock
Current local time in 8 major cities · updates every 30s
Meeting Planner
See the selected time in 8 major cities — green = business hours
Based on the date & time entered in the converter above, from the selected source zone.
| City | Local Time | Date | Status |
|---|
How It Works
UTC time = Local time − UTC offset
Target time = UTC time + Target UTC offset
// Example: 6:00 PM IST → EST
UTC = 18:00 − (+5:30) = 12:30 UTC
EST = 12:30 + (−5:00) = 07:30 AM EST
About Daylight Saving Time (DST)
DST shifts a time zone's offset by +1 hour during warmer months. The US "springs forward" on the second Sunday of March (EST becomes EDT, UTC−4) and "falls back" on the first Sunday of November. The EU changes on the last Sunday of March and October. If the source or target zone observes DST, tick the DST checkbox above to apply the +1h adjustment automatically.
Fractional Offsets Explained
Some countries don't align with the standard whole-hour UTC offsets. India uses UTC+5:30, Iran uses UTC+3:30, Afghanistan UTC+4:30, Myanmar UTC+6:30, and Nepal UTC+5:45 (the world's only quarter-hour offset). These are hardcoded in our data, so conversions to and from these zones are handled precisely.
What is a Time Zone Converter?
A time zone converter is a tool that translates a clock time from one region of the world to the equivalent local time in another region. Because the Earth is divided into approximately 24 major time zones — each offset from UTC (Coordinated Universal Time) by a whole or fractional number of hours — the same moment in time reads differently on clocks around the world. A reliable converter eliminates manual arithmetic errors, accounts for fractional offsets (like India's UTC+5:30 or Nepal's UTC+5:45), and optionally factors in Daylight Saving Time adjustments. Our converter works entirely in your browser using a hardcoded static offset table — no API calls, no network dependency, and fully offline-capable.
Understanding UTC and GMT
UTC (Coordinated Universal Time) is the modern successor to GMT (Greenwich Mean Time) and is the international standard for timekeeping. It is maintained by a network of atomic clocks and never observes Daylight Saving Time, making it a stable and universal reference point. Every time zone on Earth is defined as a positive or negative offset from UTC — for example, New York is UTC−5 (EST), London is UTC+0 in winter (GMT) and UTC+1 in summer (BST), and Mumbai is UTC+5:30 (IST) year-round. For everyday conversion purposes, GMT and UTC are interchangeable; the distinction matters only in highly precise scientific contexts where GMT uses astronomical observations while UTC relies on atomic clocks with occasional leap second adjustments.
How Daylight Saving Time (DST) Affects Time Zone Offsets
Daylight Saving Time (DST) is the practice of advancing clocks by one hour during summer months to shift an extra hour of daylight into the evening. Roughly 70 countries worldwide observe DST, though on different schedules:
- United States & Canada: Clocks spring forward on the 2nd Sunday of March and fall back on the 1st Sunday of November.
- European Union: Clocks change on the last Sunday of March (forward) and October (backward).
- Australia: DST is observed only in some states (not Queensland or Western Australia); runs October to April (opposite hemisphere).
- Countries with NO DST: India, China, Japan, most of Africa, most of Southeast Asia, and most of the Middle East maintain a constant UTC offset year-round.
When DST is active, the affected time zone's offset increases by +1h. For example, EST (UTC−5) becomes EDT (UTC−4) during US summer. Our DST checkbox allows you to apply this +1h offset manually for any zone that supports it.
Time Zones Around the World — Complete Guide
The world's 24+ time zones span from UTC−12 (Baker Island, uninhabited) to UTC+14 (Kiritimati, Christmas Island in Kiribati). Not all zones are separated by whole hours: several countries use 30-minute or 45-minute offsets for political or geographic reasons. The table below lists the most commonly used zones:
| Time Zone | UTC Offset | Major Cities | DST? |
|---|---|---|---|
| PST / PDT | UTC−8 / UTC−7 | Los Angeles, Vancouver, Seattle | Yes |
| MST / MDT | UTC−7 / UTC−6 | Denver, Phoenix, Calgary | Yes (excl. AZ) |
| CST / CDT | UTC−6 / UTC−5 | Chicago, Dallas, Mexico City | Yes |
| EST / EDT | UTC−5 / UTC−4 | New York, Miami, Toronto | Yes |
| GMT / BST | UTC+0 / UTC+1 | London, Dublin, Lisbon | Yes |
| CET / CEST | UTC+1 / UTC+2 | Paris, Berlin, Rome, Madrid | Yes |
| MSK | UTC+3 | Moscow, St. Petersburg | No |
| GST | UTC+4 | Dubai, Abu Dhabi | No |
| IST | UTC+5:30 | Mumbai, Delhi, Kolkata, Bangalore | No |
| CST | UTC+8 | Beijing, Shanghai, Singapore, HK | No |
| JST | UTC+9 | Tokyo, Osaka, Seoul | No |
| AEST / AEDT | UTC+10 / UTC+11 | Sydney, Melbourne, Brisbane | Yes (Oct–Apr) |
| NZST / NZDT | UTC+12 / UTC+13 | Auckland, Wellington | Yes (Sep–Apr) |
Tips for International Meeting Scheduling
- Find the overlap window first. Use the Meeting Planner above to see all key attendee cities at once. Green cells indicate standard business hours (9 AM–6 PM).
- Prefer morning slots in the eastern-most zone. For India–US calls, early morning in India (7:30–9 AM IST) corresponds to the previous evening in the US, while 9 AM EST = 7:30 PM IST — manageable for Indian attendees.
- Watch for DST transitions. When the US or EU shifts by one hour seasonally, the overlap window changes. Always confirm the effective offset around DST transition dates in March, October, and November.
- Use UTC as your anchor. When communicating meeting times across many zones, state the time in UTC and let each participant convert to their local time. This avoids DST confusion entirely.
- Avoid DST crossover weeks. The weeks where some regions have changed clocks but others have not (e.g., US in March before EU changes) create temporary offset shifts. Double-check conversions during these windows.
- Consider cultural working hours. Many Middle Eastern countries have a Sunday–Thursday work week, while Western countries follow Monday–Friday. This affects which days overlap for meetings.
- Time zones on the International Date Line. When scheduling between the US West Coast and Japan, Australia, or New Zealand, expect a 1-day calendar difference. A 9 AM Wednesday meeting in Sydney = Tuesday evening in London.
Frequently Asked Questions
What is UTC?
UTC (Coordinated Universal Time) is the primary time standard used worldwide, maintained by atomic clocks. It is the successor to GMT and never observes Daylight Saving Time, making it a fixed reference point from which all other time zones are defined as ± offsets. For example, IST = UTC+5:30, EST = UTC−5, JST = UTC+9.
What is the difference between GMT and UTC?
GMT (Greenwich Mean Time) and UTC share the same base time (UTC±0) and differ by less than one second in practice. GMT is a historical time zone used in certain countries (UK in winter, Portugal, Iceland), while UTC is a precise scientific standard maintained by atomic clocks with occasional leap second corrections. For everyday time conversion, GMT and UTC are effectively identical.
How do I convert IST to EST?
IST (India Standard Time) is UTC+5:30 and EST (Eastern Standard Time) is UTC−5. The difference is 10 hours and 30 minutes — subtract 10h 30m from IST to get EST. Example: 9:00 AM IST = 10:30 PM EST the previous day. When EST observes EDT (UTC−4) in summer, subtract 9h 30m instead. Use the converter above to handle this automatically.
Which countries do not observe Daylight Saving Time?
The majority of countries — about 130 of ~195 — do not observe DST. These include India, China, Japan, South Korea, Indonesia, most of Africa, most of the Middle East (except Israel and Lebanon), most of Southeast Asia, Singapore, Malaysia, most of South America, and many island nations. Only roughly 70 countries worldwide currently adjust clocks seasonally.
How does Daylight Saving Time work?
DST shifts clocks forward by 1 hour during warmer months to extend evening daylight. In the US, clocks spring forward the 2nd Sunday of March and fall back the 1st Sunday of November. In the EU, changes occur on the last Sunday of March and October. The effect: EST (UTC−5) becomes EDT (UTC−4) in summer. This 1-hour shift can alter international meeting overlap windows and must be accounted for when scheduling or converting times during transition periods.
What are UTC half-hour and quarter-hour offsets?
Most time zones are whole-hour offsets from UTC, but several countries use fractional offsets: India and Sri Lanka use UTC+5:30, Afghanistan UTC+4:30, Iran UTC+3:30, Myanmar UTC+6:30, and Nepal UTC+5:45 — the world's only quarter-hour (45-minute) offset, maintained since 1986 to distinguish Nepal from neighbouring India. All of these are supported precisely in our converter.
What is the best time to schedule an international meeting between India and the US East Coast?
The IST–EST gap is 10h 30m (or 9h 30m when EDT is in effect). For a call that falls within business hours in both countries, the only workable window is roughly 7:30 AM–9:30 AM IST = 9:00 PM–11:00 PM EST (previous day) or 8:00 PM–9:30 PM IST = 9:30 AM–11:00 AM EST (which requires India to call outside normal business hours). Most teams compromise with an early morning slot in India. Use our Meeting Planner above to visualise this across all 8 cities simultaneously.