World Time, Time Zone Converter and Date Tools
Check the current time anywhere, convert time zones, plan international meetings, and calculate dates.
Popular cities
All tools
World Clock
Current local time in cities around the world, with UTC offsets and daylight saving status.
Time Zone Converter
Convert a date and time from one time zone to up to ten others, with correct daylight saving handling.
Time Difference
Hour-by-hour time differences between major world cities, with the best hours to call.
Meeting Planner
Compare working hours across cities and find a meeting time that works for everyone.
Date Difference Calculator
Count the days, weeks, months and years between two dates.
Business Days Calculator
Count working days between two dates, excluding weekends and public holidays.
Age Calculator
Work out an exact age in years, months and days — plus the countdown to the next birthday.
Countdown Timer
Count down to any date and time in any time zone.
Stopwatch
A precise online stopwatch with lap times — runs entirely in your browser.
Online Timer
Set a countdown timer with an alarm — for cooking, workouts, study sessions and more.
Week Number Calculator
Find the ISO week number of any date, and see exactly which days each week covers.
Yearly Calendar
A printable yearly calendar with ISO week numbers and public holiday highlighting.
Sunrise & Sunset
Sunrise, sunset, twilight and day length for any city or coordinates, on any date.
Moon Phases
Current moon phase and illumination, plus new and full moon dates for any year.
Current UTC Time
Live Coordinated Universal Time, Unix timestamp and ISO 8601 — with one-click copy.
Time Zone Abbreviations
What CST, IST, CET and other abbreviations mean — and why they can be ambiguous.
What people use this for
- International meetings
- Travel planning
- Remote work
- Project deadlines
- Global customer support
- Holiday planning
Why world time still trips people up
The planet runs on one physical timeline but thousands of local conventions. Offsets come in half-hour and even 45-minute steps, daylight saving rules differ by country and change by law, and the same abbreviation can point at three different zones. Getting a call time wrong by an hour is one of the most common — and most avoidable — scheduling mistakes.
Every tool on this site works the same way under the hood: your input is converted to UTC using the IANA time zone database, calculated there, and converted back for display. That single discipline is what keeps results correct across DST transitions, leap years, month-end quirks and the international date line.
Frequently asked questions
What is my current time zone?
Your device already knows: it reports an IANA time zone such as America/New_York or Asia/Seoul. Open any city page on this site and it will show your detected zone in the time-difference line. One zone can cover many countries, and one country can span many zones.
Why does the time difference between two cities change during the year?
Daylight saving time. Regions that observe it move their clocks forward in spring and back in autumn — on different dates in different countries. Two cities that are 9 hours apart most of the year can briefly be 8 or 10 hours apart while only one of them has switched.
What is UTC?
Coordinated Universal Time is the global reference clock. Every time zone is defined as an offset from UTC (like UTC+9 or UTC-5). Aviation, computing and science use UTC so that everyone shares one unambiguous timeline; all conversions on this site go through UTC internally.
How does daylight saving time affect meetings?
A recurring meeting set for 9:00 in one city drifts by an hour for participants elsewhere whenever either side switches clocks. The safest habit is to re-check international meetings in the weeks around March/April and October/November, when most transitions happen.
Can two countries use the same time zone?
Yes, constantly. UTC+1 covers most of western and central Europe; China, Singapore, Malaysia, the Philippines and Western Australia all sit at UTC+8. Sharing an offset does not mean sharing DST rules, though — which is why IANA zone names matter more than offsets.
Why are time zone abbreviations sometimes confusing?
Because they are not unique. CST can mean Central Standard Time (UTC-6), China Standard Time (UTC+8) or Cuba Standard Time (UTC-5); IST can be India, Israel or Irish Standard Time. Use city names or IANA identifiers like Asia/Shanghai when precision matters.