⚡ Everyday Utility
🆓 Free
🌍 Global
🌍 Time Zone Converter
Convert time between any two cities or time zones instantly with automatic DST adjustment. Check the live world clock for 20+ major cities, plan meetings across time zones with a business-hours overlap view, and explore time zone facts and UTC offsets - all in one free tool.
🌍 Convert Time Between Zones
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⚡ Quick Conversions - Common Routes
🕐 Live World Clock
All times update live every second. ☀️ = Day · 🌙 = Night
📅 Meeting Time Planner
Find the best time for a global meeting. Enter a time in one zone to see it in all others.
💡 Time Zone Facts & Trivia
Total Time Zones
There are 38 unique UTC offsets in the world, ranging from UTC-12 (Baker Island) to UTC+14 (Line Islands, Kiribati). Not all offsets are whole hours - some like India (UTC+5:30) and Nepal (UTC+5:45) use 30 or 45 minute offsets.
Same Moment, Different Days
The world's largest time difference is 26 hours - between Baker Island (UTC-12) and Line Islands (UTC+14). This means two places on Earth can be on different calendar days - even different years on New Year's!
India's Unique Offset
India Standard Time (IST) is UTC+5:30 - a half-hour offset. This was chosen to split the difference between two ideal time zones. Nepal goes even further with UTC+5:45, the world's only 45-minute offset.
China's Single Time Zone
China spans 5 geographic time zones, but uses only one (UTC+8) for the entire country. This means sunrise in western China (Xinjiang) can be as late as 10am - making it one of the world's most unusual time zone decisions.
Daylight Saving Time
About 70 countries observe Daylight Saving Time (DST), moving clocks forward in spring and back in autumn. The USA, Canada, and most of Europe use DST. Countries near the equator (India, China, Japan) do not - the day length doesn't vary enough to matter.
Why Time Zones Were Invented
Before 1884, every city used solar local time - noon was when the sun was highest. Railroads created chaos: trains couldn't run on schedule when every city had a different time. The US introduced standardized time zones in 1883, adopted globally in 1884 at the International Meridian Conference.
The International Date Line
The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. Cross it heading west and you gain a day; heading east and you lose a day. Kiribati moved the IDL in 1995 to put all its islands in the same date - making it the first country to enter each new year.
Australia's Half-Hour Zones
Australia has 3 standard time zones including the quirky Australian Central Standard Time (ACST) at UTC+9:30 - a full 30 minutes offset. South Australia and the Northern Territory use this zone, making scheduling meetings across Australia particularly interesting.
📐 How Time Zone Conversion Works
Basic Conversion
All time zones are defined as an offset from UTC (Coordinated Universal Time).
Target Time = Source Time − Source UTC Offset + Target UTC Offset
Example: Convert 3:00 PM New York (UTC-5) to Mumbai (UTC+5:30)
= 15:00 − (−5) + 5.5
= 15:00 + 5 + 5.5
= 25:30 → 01:30 AM next day
Example: Convert 3:00 PM New York (UTC-5) to Mumbai (UTC+5:30)
= 15:00 − (−5) + 5.5
= 15:00 + 5 + 5.5
= 25:30 → 01:30 AM next day
UTC as the Common Language
Step 1: Convert source to UTC
UTC = Local Time − UTC Offset
Step 2: Convert UTC to target
Target = UTC + Target Offset
Example: 9:00 AM IST (UTC+5:30) → EST (UTC-5)
Step 1: 9:00 − 5:30 = 3:30 AM UTC
Step 2: 3:30 − 5:00 = 10:30 PM EST (previous day)
UTC = Local Time − UTC Offset
Step 2: Convert UTC to target
Target = UTC + Target Offset
Example: 9:00 AM IST (UTC+5:30) → EST (UTC-5)
Step 1: 9:00 − 5:30 = 3:30 AM UTC
Step 2: 3:30 − 5:00 = 10:30 PM EST (previous day)
Daylight Saving Time (DST)
DST adds 1 hour during summer months in many countries, temporarily changing the UTC offset.
New York (Eastern):
Winter: UTC−5 (EST - Eastern Standard Time)
Summer: UTC−4 (EDT - Eastern Daylight Time)
London (GMT):
Winter: UTC+0 (GMT)
Summer: UTC+1 (BST - British Summer Time)
Winter: UTC−5 (EST - Eastern Standard Time)
Summer: UTC−4 (EDT - Eastern Daylight Time)
London (GMT):
Winter: UTC+0 (GMT)
Summer: UTC+1 (BST - British Summer Time)
Crossing Midnight
If result < 0:00 → subtract 1 day, add 24 hours
If result ≥ 24:00 → add 1 day, subtract 24 hours
This is why converting between zones far apart often
results in a different calendar date.
If result ≥ 24:00 → add 1 day, subtract 24 hours
This is why converting between zones far apart often
results in a different calendar date.
❓ Frequently Asked Questions
AI Insights - Coming Soon!
AI-powered meeting time suggestions, travel schedule optimizer, and global team coordination tips.
⏳ Coming Soon - Stay Tuned!
Time Zone Converter - Instant Conversion, World Clock & Meeting Planner
Time zones are one of those things that seem simple until you actually need to get them right - and a wrong conversion can mean a missed meeting, a late delivery, or a booking at the wrong time. This converter uses the IANA timezone database, the same standard that powers every operating system and browser, so DST transitions and historical offset changes are handled correctly for any date you enter - not just today.
Three tools in one: Converter - any city to any city with DST auto-adjustment · World Clock - live time for 20+ major cities simultaneously · Meeting Planner - see business hours overlap for international teams with colour-coded availability indicators
Major World Time Zone Reference - UTC Offsets
🌏 Asia & Middle East
- IST - India Standard Time: UTC+5:30 (no DST)
- PKT - Pakistan Standard Time: UTC+5 (no DST)
- BST - Bangladesh Standard Time: UTC+6 (no DST)
- CST - China Standard Time: UTC+8 (no DST)
- JST - Japan Standard Time: UTC+9 (no DST)
- SGT - Singapore Time: UTC+8 (no DST)
- GST - Gulf Standard Time (UAE): UTC+4 (no DST)
- AST - Arabia Standard Time (Riyadh): UTC+3 (no DST)
- IRST - Iran Standard Time: UTC+3:30 (observes DST → UTC+4:30)
- WIB - Western Indonesia Time: UTC+7 (no DST)
🌍 Europe, Americas & Pacific
- GMT/UTC - Greenwich Mean Time: UTC+0 (London winter)
- BST - British Summer Time: UTC+1 (London summer, Mar–Oct)
- CET - Central European Time: UTC+1 (Paris, Berlin winter)
- CEST - Central European Summer Time: UTC+2 (Mar–Oct)
- EST - US Eastern Standard Time: UTC−5 (Nov–Mar)
- EDT - US Eastern Daylight Time: UTC−4 (Mar–Nov)
- PST - US Pacific Standard Time: UTC−8 (Nov–Mar)
- PDT - US Pacific Daylight Time: UTC−7 (Mar–Nov)
- AEST - Australian Eastern Standard Time: UTC+10
- AEDT - Australian Eastern Daylight Time: UTC+11 (Oct–Apr)
Most Common Time Zone Conversions - India to the World
India (IST, UTC+5:30) is one of the busiest international business hubs, so these conversions are looked up thousands of times daily:
- IST to EST (New York): IST is 10h 30min ahead of EST (9h 30min ahead during EDT). When it is 9:00 AM in New York (EST), it is 7:30 PM in Mumbai.
- IST to PST (Los Angeles): IST is 13h 30min ahead of PST (12h 30min ahead during PDT). When it is 9:00 AM in Los Angeles (PST), it is 10:30 PM in Mumbai.
- IST to GMT (London): IST is 5h 30min ahead of GMT. When it is 12:00 PM in London (GMT), it is 5:30 PM in Mumbai. During BST (summer), IST is 4h 30min ahead.
- IST to GST (Dubai): IST is 1h 30min ahead of GST. When it is 9:00 AM in Dubai, it is 10:30 AM in Mumbai.
- IST to SGT (Singapore): IST is 2h 30min behind SGT. When it is 9:00 AM in Mumbai, it is 11:30 AM in Singapore.
- IST to JST (Tokyo): IST is 3h 30min behind JST. When it is 9:00 AM in Mumbai, it is 12:30 PM in Tokyo.
- IST to AEST (Sydney): IST is 4h 30min behind AEST (5h 30min behind AEDT). When it is 9:00 AM in Mumbai, it is 1:30 PM in Sydney (AEST).
Daylight Saving Time - Which Countries Observe It and When
DST is one of the most common sources of time zone confusion, especially for recurring international meetings. Here is who observes it and when:
- United States and Canada: Clocks spring forward 1 hour on the second Sunday in March and fall back on the first Sunday in November. EST (UTC−5) becomes EDT (UTC−4) during this period.
- European Union: Clocks change on the last Sunday in March (spring forward) and the last Sunday in October (fall back). CET (UTC+1) becomes CEST (UTC+2).
- United Kingdom: Clocks change on the last Sunday in March and October. GMT (UTC+0) becomes BST (UTC+1).
- Australia: Southern Hemisphere reversal - clocks spring forward in October and fall back in April. AEST (UTC+10) becomes AEDT (UTC+11) in summer (their summer, October–April).
- Do NOT observe DST: India, China, Japan, Singapore, UAE, Saudi Arabia, Qatar, Pakistan, Bangladesh, most of Africa, Russia (abolished DST in 2014). These countries maintain the same UTC offset year-round - a significant advantage for international scheduling.
This converter automatically detects whether DST applies on the specific date you enter, so you always get the correct offset without manually looking up whether DST is currently active.
Planning International Meetings - The Overlap Problem
Finding a meeting time that works for participants in multiple time zones is genuinely difficult. Here are the practical overlap windows for the most common international team combinations:
- India + US East Coast: Very limited overlap. 8:00–9:30 AM IST = 9:30–11:00 PM EST previous day. Best slot: early morning India / late evening US - or use async communication.
- India + US West Coast: Even harder. 8:00 AM IST = 6:30 PM PST previous day. Most teams schedule India early morning (6:30–8:00 AM IST) to overlap with US afternoon.
- India + UK: Good overlap during UK afternoon. 2:00–6:00 PM IST = 8:30 AM–12:30 PM GMT. This is the most manageable India–Europe window.
- India + Singapore/Australia: India morning = Singapore/Sydney morning. 9:00 AM IST = 11:30 AM SGT = 1:30 PM AEST. Excellent overlap for APAC meetings.
- US East + UK: Good overlap. 9:00 AM–2:00 PM EST = 2:00–7:00 PM GMT. Both are in business hours.
- US East + US West: 3-hour gap. Best overlap window: 12:00–6:00 PM EST = 9:00 AM–3:00 PM PST. Standard business hours overlap well.
Use the Meeting Planner tab to enter your preferred time and instantly see whether it falls within working hours, outside hours, or sleep time for all your team locations simultaneously.
Why Do Some Countries Have Half-Hour or Quarter-Hour Time Zone Offsets?
Most time zones are offset from UTC by whole hours, but several countries use 30-minute or even 15-minute offsets - driven by geography, politics, and a desire to maintain a single national time zone:
- India (UTC+5:30): A half-hour offset allows a single time zone across a country spanning 30 degrees of longitude - reducing the maximum solar time deviation across the country.
- Iran (UTC+3:30): Splits the difference between neighbouring Afghanistan (UTC+4:30) and Iraq (UTC+3).
- Afghanistan (UTC+4:30): Half-hour offset between Pakistan (UTC+5) and the Middle East.
- Nepal (UTC+5:45): A 45-minute offset - the only major country with a 15-minute increment - chosen to distinguish Nepal's time from India's IST and avoid confusion.
- Australia (several states): South Australia and Northern Territory use UTC+9:30 (ACST), while New South Wales uses UTC+10 - a division driven by historical railway scheduling.