Online Alarm Clock, Timer, Stopwatch and Time Tools
Set an alarm or start a timer, time laps on the stopwatch, check sunrise and sunset, tonight's moon phase or today's tides, and compare the time anywhere on the world clock.
Open to see the full screen bedside clock.
Sunrise & Sunset
The cities below run north to south. The farther from the equator, the more day length swings with the season — long summer days, short winter ones.
Where the sun and moon are from your town, at any moment. Drag through a day, a week or a month and watch the Earth turn and the phase change.
The planets where they actually are today. Scrub a month, a year, a decade or a century, and zoom from the Earth and Moon out to Neptune.
Timers and a stopwatch built for a projector, and two astronomy simulators with the lesson written next to them — day and night, the phases, the seasons, and why the solar system will not fit on a screen.
The classroom guide →Event countdowns
Live countdowns to birthdays, holidays, sports and the days you're waiting for.
Can't find it? Suggest a birthday, holiday or event and we'll consider adding a countdown for it.
Guides: using the timer & stopwatch in a classroom · how these numbers are worked out · how it works · browser limitations · about this site.