This calculator requires the use ofJavascript enabled and capable browsers. This calculator is designed to be a fully functional alarm clock that is set to YOUR local computer time. The page border background is red before the alarm is set and after the alarm has terminated. While the alarm is counting down, the page border background is gold. Select and set a time in minutes (and a possible decimal fraction) and click on Alarm to start the alarm countdown process. If the time is set for less than a minute, set a leading 0 before the decimal, such as 0.5 to set 30 seconds. While it may not be the cheapest clock in the world, if you have set your computer's time to the Atomic Clock, it may well be the most accurate! See our less technically intense version, Online Simple Alarm Clock Display, or for audible alert needs, our Online Audible Alert Timer/Clock Display, when you have time!
