Measure Time Since an Event
Choose an exact starting moment and understand the device-clock assumptions behind an elapsed-time counter.
Pick a moment rather than just a date
A time-since counter needs a starting date and time. Midnight and noon on the same date are twelve hours apart, so leaving out the hour can change the result substantially. Enter the time in the local time zone used by your device, as stated beside the controls.
Elapsed units and calendar anniversaries
After 48 elapsed hours, a counter has measured two blocks of 24 hours. That is different from describing an anniversary as two calendar days after a date. Daylight saving transitions can make the elapsed hours between local midnights shorter or longer than 24.
The running display depends on your clock
The browser updates the counter while the page is open. An inaccurate device clock affects the displayed elapsed time, and changing the device’s time zone can change how an entered local date is interpreted. Check automatic date/time settings when a result looks consistently wrong.
Choose a different tool for other questions
Use date duration for whole calendar dates and an age calculator for completed years and months. Use the countdown for a future event. If an event happened in another city, first establish the equivalent local moment with a dated time zone conversion; an abbreviation alone may be ambiguous.
Put it into practice
Time Since Calculator
Measure elapsed time from a past date and time to now, with a live counter in total days, hours, minutes and seconds.
Time & planningDate Duration Calculator
Find the number of days, weeks, and calendar years, months and days between two dates. Choose whether to include the end date.
Date & calendarDate Countdown
Count down to a future date and time in days, hours, minutes and seconds, using your device’s local time zone.
Focus & timers