How to use the countdown timer
- Pick the date and time you are counting down to. You can also use a quick button: next New Year, or 7, 30 or 100 days from now.
- Give the event a name if you like. The clock shows days, hours, minutes and seconds left, ticking live, and also gives the weeks, total hours and weekdays remaining.
- Press Copy shareable link to get a web address that opens the same countdown for anyone, in their own time zone. The date and name are stored in the link itself and nowhere else.
The page title also shows the time left, so you can see it on a pinned or background tab.
How the countdown works
time left = target moment − current time days = floor(time left ÷ 86,400 s) hours = remainder ÷ 3,600 minutes and seconds follow
The clock reads your device's own time on every tick instead of subtracting one second each time. This keeps it correct if the tab is in the background, the laptop sleeps, or the timer is throttled by the browser. When you return to the tab, it catches up immediately.
The target is interpreted in your local time zone, including any daylight-saving change between now and then. A countdown to 09:00 on a date after the clocks change still ends at 09:00 on your wall clock, even though the real number of hours was one more or one less. Once the moment passes, the clock counts up to show how long ago it happened.
Worked example
Say it is 10:30 on 1 March 2025 and you count down to 09:00 on 15 March 2025.
- From 10:30 on 1 March to 10:30 on 15 March is 14 days.
- From 10:30 to 09:00 is 1 hour 30 minutes less, so the remaining time is 13 days, 22 hours, 30 minutes, 0 seconds.
- That is 1 week and 6 days, and 334.5 hours in total (13 × 24 + 22.5).
- Weekdays remaining: counting from 1 March (a Saturday) up to 15 March (a Saturday) there are 10 weekdays.
Time zones and shared links
A shareable link stores the date and time as typed, without a time zone. When someone opens it, it counts down to that same wall-clock time in their time zone. That is right for events that happen at local midnight everywhere, such as New Year, a school holiday or a sale starting in each shop's own time. It is not right for a single moment shared across zones, like a live-stream at 20:00 in London.
For a one-moment event, check the exact time for each viewer with the time zone converter, and tell them to set the date and time in their own zone. The link never includes your name, location or anything else about you.
Ideas for using a countdown
- Count to a deadline such as an exam, a visa appointment or a project launch, and keep the tab pinned.
- Send a friend the link to a birthday or a wedding countdown.
- Use the weekdays-left figure to plan working time before a due date. For a version that also skips public holidays, use the working days calculator.
- Open it on a screen during a presentation or a classroom activity to show time left.
Time left in different units
| Period | Hours | Minutes | Seconds |
|---|---|---|---|
| 1 day | 24 | 1,440 | 86,400 |
| 1 week | 168 | 10,080 | 604,800 |
| 30 days | 720 | 43,200 | 2,592,000 |
| 100 days | 2,400 | 144,000 | 8,640,000 |
| 365 days | 8,760 | 525,600 | 31,536,000 |
| 366 days (leap year) | 8,784 | 527,040 | 31,622,400 |
These are for plain 24-hour days. If your countdown crosses a daylight-saving change, the real number of hours is one more or one less, but the clock still ends at the same local time. Pick the date, not the number of hours, when you set a target so that it lands where you expect.
Accuracy and limits
The countdown is exact to the second, and relies on your device's clock being correct. If your computer's clock is wrong by a minute, the countdown will be too. It does not alert you when the time arrives; leave the tab open, or use the stopwatch and timer tool for an alarm. Very long countdowns of many years work, but the percentage figure measures progress from the moment you opened the page, not from when you first planned the event.
Frequently asked questions
Does the countdown keep running if I close the tab?
No, the clock only runs while the page is open. But the link holds your date, so reopening it restarts the correct countdown instantly.
Which time zone does the countdown use?
Your device's local time zone. The same link opened in another country counts down to the same local clock time there.
Is my event saved on a server?
No. The name and date live in the web address after the # sign, which browsers do not send to servers. Nothing is stored in a database.
Will it make a sound when it reaches zero?
No. For an alarm, use the stopwatch and timer tool, which has one. This page changes to a count-up once the time has passed.
Why is the tab title changing?
It shows the time left so you can read the countdown from a background tab. It returns to normal when you reset or leave the page.