Convert time across 175+ global timezones instantly. Compare multiple time zones, schedule international meetings, and automatically adjust for DST.
Source Time
Time Zone Comparisons
View:
Showing 175+ timezones💡 Tip: Press Enter to add or double-click a timezone
Meeting Time Finder
Find optimal meeting times that work across all selected time zones (uses standard Western business hours: 9 AM - 6 PM as reference)
⌨️ Keyboard Shortcuts:Ctrl+C Copy times
Ctrl+R Reset
Ctrl+N Use current time
Ctrl+G Toggle grid/list
How the Time Zone Calculator Works
🌐 Understanding Time Zone Conversion
Our time zone calculator uses JavaScript's Intl API, which is based on the IANA Time Zone Database (also known as the Olson database or tz database), to provide accurate time conversions across all global regions. The calculator automatically accounts for:
UTC Offsets: Each timezone's offset from Coordinated Universal Time (UTC)
Daylight Saving Time (DST): Automatic adjustments when regions observe DST
Historical Changes: Browser-supported timezone rule changes and offset modifications
Regional Variations: Specific timezone rules for different countries and regions
⚙️ How Calculations Work
When you select a source time and timezone, the calculator:
Converts your input to UTC (the universal reference point)
Applies each target timezone's offset and DST rules
Displays the equivalent local time for each selected region
Updates in real-time as you modify the source time
💡 Pro Tip: The calculator stores your preferred timezones in your browser, so they'll be remembered when you return!
🤝 Meeting Time Finder
The Meeting Time Finder analyzes all selected timezones to suggest meeting times that fall within standard Western business hours (9 AM - 6 PM) for all participants. This helps you schedule international calls that avoid early morning or late evening hours for team members. Note: Business hour norms vary by culture - some regions may start earlier (8 AM) or work later (7-8 PM).
Tips for Effective Time Zone Management
🎨 Using Visual Indicators
Color-coded time periods: Cards are automatically color-coded by time of day (morning=yellow, afternoon=blue, evening=orange, night=purple) to help you avoid late-night calls
Business Hours badges: Green "Business Hours" badges indicate 9 AM-6 PM (standard Western business hours), red "After Hours" shows outside this range
Relative time display: Quickly see how far ahead or behind each timezone is (e.g., "8h ahead" or "3h 30m behind")
Date change indicators: "Tomorrow" or "Yesterday" badges alert you when the date differs from your source timezone
Grid vs List view: Use List View for detailed comparison of 2-5 zones, or Grid View to monitor 6+ zones simultaneously
🔍 Finding Time Zones Quickly
Search functionality: Type any city, country, or timezone name to instantly filter the 175+ available timezones
Quick add buttons: Use the preset buttons for popular cities (NYC, London, Tokyo, etc.) for instant addition
Keyboard shortcuts: Press Enter after typing a search term to add the first matching timezone
Double-click to add: Double-click any timezone in the list to add it immediately without clicking the button
Coverage: Support for 175+ major cities worldwide covering all UTC offsets from UTC-11 to UTC+14
✅ Best Practices
Always specify the timezone: When scheduling meetings, always include the timezone to avoid confusion (e.g., "3 PM EST" not just "3 PM")
Use 24-hour format for clarity: Consider using 24-hour time format (15:00 instead of 3 PM) to eliminate AM/PM ambiguity
Account for DST transitions: Be extra careful when scheduling near DST change dates (typically March and November in North America/Europe, October/April in Southern Hemisphere)
Understand cultural work hours: The 9 AM-6 PM "business hours" used by this calculator reflects Western norms. Many cultures have different schedules: Mediterranean countries often have later start times and long lunch breaks, Asian countries may start earlier (8 AM), and Middle Eastern countries typically work Sunday-Thursday.
Add buffer time: For international meetings, schedule 5-10 minutes later than calculated to allow for timezone confusion
Confirm in writing: Send meeting invites that include the time in each participant's local timezone
⚠️ Common Mistakes to Avoid
Assuming DST applies everywhere: Not all countries or regions observe Daylight Saving Time
Ignoring date changes: Converting evening times can result in the next day in other timezones
Confusing EST vs EDT: EST (Eastern Standard Time) and EDT (Eastern Daylight Time) are different - use specific timezone names
Forgetting about half-hour timezones: Some regions use :30 or :45 minute offsets (like India, Nepal, parts of Australia)
Using outdated timezone data: Always use current timezone databases as rules change occasionally
🎯 Productivity Hack: When working with remote teams, keep a world clock widget on your desktop showing all key team member timezones. This helps you avoid scheduling meetings at inappropriate local times.
🔄 Handling DST Transitions
During DST transitions (dates vary by region - typically March/November in North America and Europe, October/April in Southern Hemisphere):
Spring forward (losing an hour): The 2 AM hour doesn't exist in most regions - times jump from 1:59 AM to 3:00 AM
Fall back (gaining an hour): Times from 1 AM to 2 AM occur twice
Different regions change on different dates, so international time differences can temporarily shift
Many regions (including Arizona, Hawaii, most of Saskatchewan, Japan, China, India, and most of Africa) don't observe DST at all
📱 For Remote Teams
Create a shared calendar with timezone visibility
Use tools that automatically convert times for recipients
Establish "core hours" where team members overlap
Rotate meeting times to share the burden of off-hours meetings
Record meetings for those who can't attend live
Frequently Asked Questions
Our calculator uses JavaScript's Intl API, which implements the IANA Time Zone Database - the global standard maintained by timezone experts and used by operating systems worldwide. The database is regularly updated to reflect timezone rule changes, DST adjustments, and geopolitical changes. For current and recent dates (within the last 10-20 years), accuracy is excellent. For historical dates before 1970, data availability varies by region, as complete timezone records weren't maintained universally. The calculator is most reliable for dates from 1970 onwards.
Several regions use non-standard timezone offsets that aren't full hours from UTC. For example, India uses UTC+5:30, Nepal uses UTC+5:45, and parts of Australia use UTC+9:30. These were often established for historical, geographical, or political reasons. Our calculator handles all these variations automatically, so you don't need to worry about the math!
EST (Eastern Standard Time) is UTC-5 and applies during winter months. EDT (Eastern Daylight Time) is UTC-4 and applies during summer months when Daylight Saving Time is in effect. ET (Eastern Time) is a general term that refers to whichever is currently in effect. When scheduling meetings, it's best to use specific timezone identifiers like "America/New_York" which automatically handles the EST/EDT transition.
First, add all relevant timezones using the quick buttons or search. Then use the "Meeting Time Finder" feature to identify times within standard Western business hours (9 AM - 6 PM) for all zones - though be aware that business hour norms vary globally. When sending invites, include the time in each participant's local timezone to prevent confusion. For example: "Meeting at 10 AM EST / 3 PM GMT / 11 PM JST." Consider rotating meeting times for regularly scheduled calls to share the burden of off-hours participation.
Yes! Once the page is loaded, all calculations happen in your browser using JavaScript. You don't need an internet connection to convert times. Your saved timezone preferences are stored locally in your browser, so they'll persist even offline. However, you will need to be online initially to load the page.
The calculator automatically handles DST transitions. In spring when clocks "spring forward," the 2 AM hour is skipped (jumps to 3 AM). In fall when clocks "fall back," times between 1-2 AM occur twice. Different countries transition on different dates, so be extra careful scheduling meetings around March and November. Some regions like Arizona and Hawaii don't observe DST at all.
Yes! There's no hard limit on the number of timezones you can add. Use the "Add Time Zone" dropdown to keep adding as many as you need. The calculator will display all of them in an easy-to-read format. However, for optimal performance and readability on mobile devices, we recommend keeping it to 10 or fewer timezones at a time.
The timezone list includes major cities that represent timezone regions. If your specific city isn't listed, select a major city in the same timezone. For example, if you're in Philadelphia, select "New York" since they share the same timezone. The timezone names follow the format "Region/City" (like "America/Chicago" or "Europe/Paris") for clarity and precision.
The calculator automatically knows which regions observe DST and which don't. Most countries near the equator (including most of Africa, Southeast Asia) don't observe DST due to minimal seasonal daylight variation. Additionally, major economies like China, Japan, India, and South Korea don't use DST. North America and Europe generally do observe DST, though with exceptions (Arizona, Hawaii, Saskatchewan). You'll see a "DST" indicator badge when Daylight Saving Time is currently in effect for a timezone.
For remote teams: (1) Establish "core hours" where everyone overlaps, (2) Rotate meeting times to share the burden of off-hours calls, (3) Record meetings for those who can't attend live, (4) Use calendar tools that show times in each person's local timezone automatically, and (5) Be mindful of weekend differences - Friday evening in New York is already Saturday morning in Sydney! Always confirm meeting times in writing with each person's local timezone clearly stated.
The calculator includes 175+ major cities covering every timezone from UTC-11 to UTC+14. Use the search box to find your city by typing its name - it will instantly filter the list. If your specific city isn't listed, select a major city in the same timezone. For example, if you're in Philadelphia, select "New York" since they share the same timezone (America/New_York). You can also search by country name or UTC offset.
There are several quick methods: (1) Click the preset buttons at the top for popular cities, (2) Type a city name in the search box and press Enter to add the first match, (3) Double-click any timezone in the list to add it instantly, or (4) Use the traditional method of selecting and clicking "Add Time Zone". The search box supports partial matches, so typing "paris" will find "Paris (UTC+1:00)".
List View (default) displays timezones in a single column with full details, ideal for comparing 2-5 timezones. Grid View arranges timezones in a 2-3 column layout, perfect for monitoring many timezones at once. Switch views using the toggle buttons or press Ctrl+G. Your preference is automatically saved for future visits.
Each timezone card is color-coded by conventional time-of-day periods: yellow/gold for morning (6 AM-12 PM), blue for afternoon (12 PM-6 PM), orange for evening (6 PM-10 PM), and purple for night (10 PM-6 AM). These classifications are based on typical Western conventions and help you quickly identify if you'd be contacting someone during typical sleep hours. Cards also show "Business Hours" (green) or "After Hours" (red) badges based on the 9 AM-6 PM standard business day.
The relative time indicator (e.g., "8h ahead" or "3h 30m behind") shows the time difference from your source timezone. This makes it easier to mentally calculate time differences without doing math. For example, if it's 2 PM in your timezone and a location is "5h ahead," you know it's 7 PM there.