The short answer
Type a name such as Our wedding, pick the date, and set the time if the moment matters (a ceremony at 3 pm, a product launch at 10:00). The countdown starts at once and shows days, hours, minutes and seconds. Press Share with these settings under the tool to copy a link that contains the name, date, time and time zone. Anyone who opens that link sees the same countdown, ticking toward the same second.
For a party, a classroom or a shop window, press Full screen. The numbers fill the screen, and the screen stays on while the countdown is shown in full screen.
Try it here: Countdown to a Date
Open the full tool pageChoose the right moment: date, time and time zone
A countdown counts to one exact instant, so three things define it: the date, the time and the time zone. If you leave the time at 00:00, the countdown ends at midnight at the start of that day, which suits birthdays and holidays. For anything that happens at a set hour, enter the hour: for a wedding ceremony at 15:00 the countdown should reach zero at 15:00, not at the midnight before.
The time zone matters as soon as people in more than one place follow the same countdown. When you change the date or time, the tool records your own time zone in the link. A friend in another country then counts to the same instant and sees an extra line with their local time. If the event happens somewhere else, pick that place in Time zone: a launch at 10:00 in Los Angeles should be set with a Los Angeles city, even if you live in London.
- Birthdays, holidays, anniversaries: the date is enough, keep 00:00 and your own time zone.
- Weddings, concerts, flights, exams: enter the exact start time.
- Online launches, live streams, game releases: use the organiser's time zone.
- Family spread across countries: use the time zone of the place where the event happens.
Step by step with the tool on this page
The tool has four fields under the countdown: Event name, Date, Time and Time zone. The name appears above the numbers, so keep it short enough to read from across a room. The date and time fields use your device's normal pickers, and the Time zone field lets you search for a city. Use my time zone switches back to your own zone.
Below the large numbers you see when the countdown ends, written out in full with the time zone, and, if the event is in another zone, the same moment in your local time. A row of boxes adds days on the calendar, weeks, total hours and total minutes. If you want an alert, turn on Play a sound at the end, choose a sound and press Test to check the volume. The tab must stay open for the sound to play.
Sharing the countdown
Share with these settings copies the current address. The settings sit after the # sign, for example #title=Our%20wedding&date=2027-06-12&time=15%3A00&zone=Europe%2FIstanbul. That part of an address is never sent to a server by the browser, so the event name is not stored anywhere except in the link itself and in the browser of whoever opens it.
Send the link in a chat, an email or a calendar invite. Because the time zone travels with the link, the countdown does not shift when someone opens it on the other side of the world. If you change the date later, copy the link again: old links keep the old date.
On the main countdown page your last countdown is also remembered in your browser, so you can close the tab and come back to it. Opening a shared link shows that link's countdown instead.
Clock changes, leap years and other traps
Daylight saving time is the classic trap. In the US the clocks go back on the first Sunday of November, in the EU on the last Sunday of October, and forward again in March. A countdown that simply counts wall clock hours would be one hour off after such a change. This tool computes the target instant with the time zone rules built into your browser, so it ends at the right moment, and the hours it shows are real elapsed hours. The night of the change has 23 or 25 of them.
Leap years and month lengths are handled the same way: the countdown works from actual instants, not from an average month. If you pick a time that does not exist because the clocks jump forward (for example 02:30 on the night clocks go from 02:00 to 03:00), choose a time outside that hour.
| Situation | What the countdown does |
|---|---|
| Clocks go back one hour before the event | Ends at the right instant; that night has 25 hours |
| Clocks go forward one hour before the event | Ends at the right instant; that night has 23 hours |
| Link opened in another time zone | Same remaining time, plus a line with the local time |
| Date already passed | Shows zeros and a short message |
| Device clock set wrong | Counts from the wrong clock; turn on automatic time |
Days left versus days on the calendar
People mean two different things by days until. The large numbers show complete days plus hours, minutes and seconds. The box Days on the calendar counts date changes, the way you count on a wall calendar or the way children count sleeps. At 3 pm on 27 October, Christmas Day is 58 full days and 9 hours away but 59 days on the calendar. Both are correct; use the one your audience expects.
Weeks are shown with one decimal (8.4 weeks), which is handy for pregnancies, training plans and project schedules that are planned in weeks.
Ideas and ready made countdowns
Common countdowns include weddings, holidays, a move to a new home, retirement, exams, the start of school, a due date, a product launch, a game or film release and the end of a fixed term contract. For yearly events the site has ready pages that always point to the next occurrence in your own time zone: days until Christmas, the New Year countdown and the Valentine's Day countdown. They switch to the following year by themselves once the day is over.
For short durations, such as ten minutes for a talk or a cooking timer, a simple timer is the better tool, because you set a length rather than a date.