Master Global Time, Effortlessly
A precise, beautifully designed suite of time tools — synced to the world's atomic clocks, used by professionals in 180+ countries.
Direct Answer
Need an instant time answer? Our tools automatically detect your location to provide accurate time zone conversions, meeting overlaps, and date durations. For example, the time difference between New York (EST) and London (GMT) is exactly 5 hours.
Your Time Toolkit
Everything you need to stay in sync — free, fast, no signup.
Custom Calendar
Generate a printable calendar for any year, with holidays.
Build my calendarAdd/Subtract Dates
Find the date 90 days from now, or 6 weeks before that deadline.
Calculate a future dateDate Duration
How many days between two dates? Get a years-months-days breakdown.
Measure a date rangeAge Calculator
Find your exact age in years, months, days — down to the day.
Calculate my ageCountdown Timer
Set a timer for your important events and deadlines.
Start a countdownStopwatch
Measure elapsed time with laps, in your browser.
Open the stopwatchAlarm Clock
Set a browser-based alarm that works while the tab is open.
Set an alarmMoon Phases
See the current phase and the full lunar calendar for any month.
View the moon tonightWeek Number
Find the ISO week number for any date, in any year.
Find a week numberA free tool that doesn't act like one.
We treat time data the way an airline treats a flight schedule: as safety-critical information that has to be right.
Synced to atomic clocks
Every time you see is traceable to NIST and BIPM reference clocks. We don't guess — we sync.
How we syncComputed in-house
Sun, moon, and astronomical data are computed with pure math — no third-party APIs in the critical path.
See our mathCalibrated to NASA JPL
Astronomical angles and phases verified against the NASA Jet Propulsion Laboratory's Horizons system.
Read about JPLSunrise & Sunset Calculator
Planning a photoshoot, a hike, or just curious about daylight hours? Get precise sunrise, sunset, golden hour, and twilight times for any location on any date — with a live 3D view of the day/night terminator.
Frequently Asked Questions
Quick answers to common time-related questions.
Save 5 hours a week on scheduling.
One short email each Friday: a scheduling tip, an upcoming DST change, and one time-zone trick used by our team.