Compare time across any city, instantly.
Add places, pick a date, and move the cursor to see the same moment worldwide. Drag across the grid to select a meeting window and find the best overlap for your team.
Tools
Browse by abbreviation
How it works
Add cities
Search 33,000+ cities or any timezone abbreviation (EST, GMT, IST). Saved automatically.
Read at a glance
Color-coded periods show business hours, evening and sleep — see who's awake instantly.
Plan the meeting
Drag to select a window and see overlap quality, then export to calendar.
Background
Understanding time zones
The world is divided into 24 standard time zones, each roughly 15 degrees of longitude wide and anchored to Coordinated Universal Time (UTC). New York is UTC−5 in winter and UTC−4 in summer (EST/EDT).
Real-world zones are messier than the grid suggests. India holds a single offset (UTC+5:30) from Mumbai to Kolkata; Russia spans 11. Nepal sits on UTC+5:45 — a 45-minute offset that breaks naive arithmetic.
Daylight Saving is another wrinkle. ~70 countries observe it, on different dates and in opposite hemispheres. When the US springs forward, Australia has already fallen back — so the offset between Sydney and New York shifts twice a year. AllTimeZone handles all of this from the IANA database automatically.
FAQ
How do I compare times between multiple cities?
Use the search bar above the time grid to add any city or timezone abbreviation. You can add as many locations as you need. The 24-hour grid shows each city's local time side by side, with color-coded periods for business hours, evening, and sleep time.
How does the meeting planner work?
Click and drag across the time grid to select a meeting window. AllTimeZone will instantly show the local time for each participant and rate the overlap as good (all in business hours), acceptable (some in evening), or poor (someone is in sleep hours). You can then export to Google Calendar or download an ICS file.
What is Daylight Saving Time and how does it affect time zones?
Daylight Saving Time (DST) is the practice of advancing clocks by one hour during warmer months to extend evening daylight. Not all countries observe DST, and those that do change on different dates. AllTimeZone automatically accounts for DST transitions using the IANA timezone database, so times are always accurate regardless of the time of year.
How accurate is AllTimeZone?
AllTimeZone uses the IANA Time Zone Database (also called the Olson database), the same authoritative source used by operating systems like macOS, Linux, Android, and iOS. Times are accurate to within seconds, including automatic DST adjustments. Our database covers 33,000+ cities worldwide.
Can I share my timezone comparison with others?
Yes — click the Share button above the time grid to copy a link that includes your selected cities, date, and meeting window. Anyone who opens the link will see the exact same view, making it easy to coordinate across teams.
What timezone abbreviations does AllTimeZone support?
AllTimeZone supports all major timezone abbreviations including EST, EDT, CST, CDT, PST, PDT, GMT, BST, CET, CEST, EET, IST, JST, HKT, SGT, AEST, AEDT, MSK, TRT, and many more. You can search by abbreviation or by city name.