// Time
Countdown Timer online
Count down to any event, date or deadline — live real-time display
by
CHUNKY
MUNSTER
MUNSTER
A countdown timer creates a live, ticking display of time remaining until an event. Unlike a simple date subtraction, the timer updates every second and shows the breakdown across days, hours, minutes, and seconds — useful for event pages, project deadlines, product launches, and personal milestones.
The countdown subtracts the current client time from the target date using JavaScript's Date object, which operates in your browser's local timezone. For events with a specific timezone (e.g. a conference in New York when you are in London), specify the event's local time and note that the timer reflects your device's current time. The tick interval is 1 second; actual precision is ±50ms due to JavaScript timer scheduling.
Modern browsers throttle timers in background tabs to reduce CPU usage. The displayed count may momentarily fall behind but self-corrects when the tab is brought to the foreground, because it re-reads the system clock on each update rather than decrementing a counter.
The target date can be encoded in the URL parameters. Copy the page URL after setting your date — sharing it with others will load the same countdown in their browser (in their local timezone).
The timer shows 00:00:00 and optionally displays a custom "time's up" message. Browser notifications are triggered if you granted notification permission. The timer does not go negative.
Enter any past date — the timer switches to count-up mode automatically, showing how much time has elapsed since that moment.
See also the Date Calculator, Days Until, and the World Clock for timezone reference.