How the countdown works
A countdown measures the gap between now and a fixed target date and time. Because the ticking is relative, every open tab counts down to the same instant — which is exactly why a shared link works: everyone watching is counting the same seconds to the same moment.
Use presets for dates that never move, or set your own for birthdays, exams, product launches and trips. Fullscreen mode turns the timer into a projection-ready display for events and classrooms.