How to use the countdown timer
- Make sure the Countdown tab is selected.
- Pick a target date and time in the field — your browser's own date picker makes this quick. The shortcut button sets it to the end of today.
- The big day / hour / minute / second figures start ticking down immediately and update every second.
- When the moment arrives, the timer stops and shows “Time is up!”.
How to use the stopwatch
- Switch to the Stopwatch tab. The display reads mm:ss.cs — minutes, seconds and centiseconds (hundredths of a second).
- Press Start to begin timing. The button becomes Resume after a pause.
- Press Lap while it runs to record a split; each lap shows both the time since the previous lap and the total elapsed time, newest at the top.
- Press Pause to hold the clock, or Reset to clear everything back to zero.
Why a single tool for both?
Counting down and counting up are two sides of the same coin, and most people reach for them in the same moments — timing a presentation while also watching the clock to the deadline, or running a workout interval before the big event. Keeping both in one page means there is nothing to install and no second tab to juggle. The countdown is read straight from your device's clock, so it is always accurate even if you leave the page and come back. The stopwatch keeps its own elapsed time in memory, so switching to the countdown to glance at a deadline will not lose your timing.
Accuracy and how it works
The countdown compares your chosen target to the current time and recalculates once a second, so it never drifts — even if the tab is briefly inactive, the next tick shows the true remaining time. The stopwatch measures elapsed time from real timestamps rather than counting interval ticks, which means it stays accurate to the centisecond regardless of how busy your device is. Each timer carefully clears its own background ticker when you pause, reset or switch modes, so they never stack up or run in the background unnoticed.
Handy things to time
- Deadlines & launches: count down to a product release, a sale ending or a project due date.
- Study & work: run focused sessions, or time how long a task really takes.
- Cooking & chores: set the end-of-today shortcut, or time a brew, a bake or a quick job.
- Sport & fitness: use the stopwatch with laps for intervals, sprints or circuit training.
Is it private?
Completely. The countdown and stopwatch run in JavaScript right inside this page using your device's own clock. The date you pick and the times you measure never leave your browser — there is no server call, no account and no tracking. Close the tab and nothing is stored or sent anywhere.
Frequently asked questions
What does the “cs” in mm:ss.cs mean?
It stands for centiseconds — hundredths of a second. So 01:23.45 is one minute, twenty-three seconds and forty-five hundredths. This gives the stopwatch fine resolution for timing short bursts.
Can I count down to a date months or years away?
Yes. The countdown shows days as well as hours, minutes and seconds, so it happily handles targets that are weeks, months or years ahead — ideal for big milestones and event countdowns.
Will I get an alarm sound when the countdown ends?
The timer displays a clear “Time is up!” message when it reaches zero. It is a silent, visual countdown by design, so it will not surprise you with sound in a quiet room or shared space.
Does closing the tab keep the stopwatch running?
No. Everything lives in the page, so closing or reloading the tab resets it. While the tab stays open you can freely switch between the countdown and the stopwatch without losing your stopwatch time.