Time, counted carefully
See how long is left—and what the calendar actually does.
Countdown clocks, kitchen timers, and date math that document leap years, month-end overflow, and time zones instead of hiding them.
Quick countdown
Set a target, then start. Remaining time is computed from timestamps, not by subtracting one each second.
Popular tools
Countdown Timer
Count down to a date and time with pause, presets, and a shareable link.
Online Timer
Set hours, minutes, and seconds. The remaining time is tracked from timestamps.
Stopwatch
Start, pause, and record laps with millisecond display.
How Long Until
See days, hours, minutes, and seconds remaining until a clock time or date.
Days Until
Count the days, weeks, and months remaining until a target date.
Time Calculator
Add or subtract hours, minutes, and seconds across multiple durations.
Date Calculator
Find the difference between dates or add days, weeks, months, years, and business days.
Age Calculator
Calculate years, months, and days between a birth date and a target date.
Time Zone Converter
Convert a date and time between IANA time zones, including DST.
Event Countdowns
Live countdowns to recurring holidays and notable dates.
Countdown tools
Time tools
Date tools
Calendar tools
Event countdowns
How it works
- Pick a tool that matches the question: remaining time, elapsed time, or calendar arithmetic.
- Enter dates and times. Invalid values are rejected instead of being silently coerced.
- Live tools subtract from a stored timestamp so the number stays honest if the tab sleeps.
Why these tools
Date math fails in predictable ways: February 31, DST gaps, birthday-on-leap-day. Each calculator states the rule it uses. There are no accounts, no social publishing features, and no invented usage statistics.
Questions
Do these calculators use my local time?
Interactive tools read the current time from your browser and convert wall times with IANA time zones. The server does not assume its own zone is yours.
Why can a countdown jump after I leave a tab open?
Browsers slow background timers. These tools store a target timestamp and subtract Date.now() on each tick, so returning to the tab corrects the display.
Is an account required?
No. Preferences stay in local storage on your device. Nothing here is a signed-in product or a social publisher.