World Clock, Time Zone Converter & Countdown
See real-time clocks for cities worldwide, convert time zones, plan meetings, run timers and stopwatches, and share countdowns to the events that matter - all free.
Essential tools
World Clock
Check current time in cities around the world
Time Converter
Easily convert time between two cities
Countdown
Time remaining until holidays and events worldwide
More tools
Timer
Free online timer with alarm sound. Set any duration and start with one click.
Clock
A beautiful fullscreen clock for classrooms, cafes, gyms, and streamers
Today
Today's holidays and historical events
Awake
Real-time estimate of how many people are awake on Earth
Population
Real-time world population estimate based on UN data. View births, deaths, and regional statistics.
Date Calc
Calculate your exact age from your date of birth
Year Progress
Visualize how much of the year has passed in real time
Articles
In-depth articles about time and timezones
Glossary
Key terms about time and timezones explained
Popular Articles
Staggered Commuting - The Productivity Gains of Flexible Start Times
Staggered commuting means employees choose from a few fixed start times, such as 7:00, 9:00 or 10:00, instead of one rigid schedule. Learn how it differs from flex time, what it does for commute stress and productivity, and how to design a policy that works.
LifestyleCalculating Flight Arrival Times - Working Through Time Differences
A flight's arrival time is the local departure time plus the flight duration plus the time zone offset. Worked examples cover east-bound, west-bound, connecting and DST-affected flights, so you can check exactly when you land in local time.
TechnologyPython Timezone Handling - zoneinfo vs pytz Explained
Python 3.9 introduced zoneinfo as the standard library solution for IANA time zones, but the long-established pytz package remains in many codebases. This article compares the two, explains the naive vs aware boundary, and covers practical pitfalls including Windows tzdata, the fold attribute, and migration strategy.
TechnologyHow to Check and Configure MySQL Time Zones - Server, Connection, and Column Behavior
MySQL timezone bugs almost always trace back to a misunderstanding of three layers: server defaults, session settings, and column types. This article explains why TIMESTAMP and DATETIME behave differently, how the time_zone variable interacts with connections, and how to configure JDBC drivers correctly.
TechnologyHow TOTP Works - The 6-Digit Code Behind Google Authenticator
The 6-digit codes shown by Google Authenticator and similar apps are generated from a shared secret and the current time. This article explains the TOTP algorithm defined in RFC 6238, the difference from HOTP, common time-drift failure modes, and what is actually inside the QR code you scan during setup.
TechnologyDesigning a Timezone Conversion API - Robust Endpoints for Real Apps
Building a timezone conversion API sounds simple but quickly hits IANA database management, DST gap handling, error semantics, and caching strategy. This article covers the design decisions that determine whether the endpoint stays reliable as policies and tzdata evolve.