How the timer keeps time
The countdown does not add up ticks. When you press Start it records the finish instant as the current clock reading plus the time remaining, then redraws the display several times a second by subtracting the current time from that finish instant. This matters because browser timers drift: a tab in the background can have its callbacks throttled to once a second or less, and counting ticks would slowly lose time. Reading the real clock each frame means the timer is accurate to within a fraction of a second no matter how long it runs or how busy the machine is.
Pause stores whatever is left and stops the interval. Start picks it up from there with a fresh finish instant. Reset reads the minutes and seconds boxes again and puts the timer back to the full amount. The tab title updates as the countdown runs, so you can switch to another window and still glance at the time left along the top of your browser.
Presets and practical uses
The presets cover the lengths people ask for most: one minute for a plank or a speed round, three minutes for steeping tea or a boiled egg, five minutes for a break, ten minutes for a meeting segment and twenty-five for a focus block. Type any other value into the boxes, up to 99 hours, and press the set button. A worked example: enter 7 minutes and 30 seconds and the display reads 07:30, which is 450 seconds; the results panel confirms both figures so you know the timer took what you meant.
Common uses include cooking, interval training, timed tests and speeches, board games, medication reminders, and keeping meetings on schedule. For studying, the twenty-five minute preset matches a standard pomodoro; a dedicated pomodoro tool that cycles focus blocks and breaks automatically is linked below.
Limits worth knowing
Everything runs in your browser and nothing is stored on a server. The page has to stay open for the countdown to keep running, and a phone that locks its screen may suspend the tab, in which case the elapsed time is still correct when you return because the finish instant was recorded in advance. There is no sound alert, so keep the tab visible or watch the title bar if you need to catch the finish. Closing or reloading the page clears the timer and it starts again from the values in the boxes.