How accurate is this clock?
Our clock follows your device. Enable automatic time in your settings; this site does not independently synchronize with an atomic clock.
Named IANA time zones use your browser’s rules for daylight saving. Keep your browser and operating system updated.
Calendar conventions
Date differences count calendar dates, not elapsed hours. The start date is excluded unless inclusive counting is selected. Weekdays mean Monday–Friday without holiday exclusions. Ages use complete years, months, and days; February 29 birthdays use February 28 in common years for the next-birthday result.
ISO weeks start on Monday. Week 1 contains the first Thursday of the year.
Timer limitations
Countdowns use a target device-clock time; stopwatches use a monotonic browser clock. Background tabs, device sleep, clock corrections, muted sound, and closing the page can affect timing or alerts. Keep the page open and device awake for timely alerts.