2 Hour Timer
A two-hour countdown with an alarm for the jobs that come round every couple of hours — leftovers, sunscreen and screen breaks.
2 Hour Timer
2 hours
Ready
Keys: Space start / pause · R reset · + add a minute · F full screen · Esc stop alarm
How it keeps time
- Length: 2 hours = 7,200 seconds.
- On Start: end time = the moment you start + 7,200 s, read from your device’s clock.
- Every update: time left = end time − now, rounded up to the whole second — so it never drifts, even in a background tab.
Three two-hour rules
- Food left out. Bacteria grow fastest between 40 °F and 140 °F — the USDA’s “danger zone”. The USDA Food Safety and Inspection Service says to discard perishable food such as meat, poultry, eggs and casseroles that has been at room temperature for more than two hours, or more than one hour above 90 °F. Start this timer when the food goes on the table at a party.
- Sunscreen. The FDA advises reapplying sunscreen at least every two hours, and more often if you are swimming or sweating. Labels that say “water resistant” must state whether the protection lasts 40 or 80 minutes in water, so follow the label when you’re in the pool.
- Screen breaks. Along with the 20-20-20 rule, the American Optometric Association recommends a 15-minute break after two hours of continuous screen use. Pair this timer with the 15 minute timer for the break.
Staying accurate for two hours
Browsers deliberately slow down timers in background tabs, and over two hours a timer that counts seconds one by one can fall well behind. This one never counts: it saves the end time when you press Start and subtracts the current time whenever it updates, so the display is right the moment you look. The remaining time also appears in the browser tab. If your device sleeps, the alarm plays when it wakes. For even longer countdowns, the countdown timer goes up to 99 hours.
How this timer works
Press Start, tap the digits or press Space. The timer saves the end time on your device’s clock and shows end time − now, rounded up to the second, so it stays exact even when your browser slows down background tabs; the remaining time also shows in the tab’s title. The alarm is scheduled on the Web Audio clock for the end time and beeps for up to a minute (phones that support it also vibrate). While the timer runs, the page asks the browser to keep the screen on. Nothing is sent anywhere: the timer runs entirely in your browser.
Other timers
Shorter: 1 Hour Timer. Longer: Pomodoro Timer. For any other length, use the countdown timer; to time how long something takes, use the stopwatch. Counting down to a date instead? See the holiday countdowns.
Frequently asked questions
What is the 2-hour rule for food?
The USDA says perishable food shouldn’t be left at room temperature for more than two hours — one hour if it’s above 90 °F — because bacteria multiply quickly between 40 °F and 140 °F.
How often should I reapply sunscreen?
At least every two hours, according to the FDA, and more often if you’re swimming or sweating; water-resistant sunscreens state whether they last 40 or 80 minutes in water.
Will a 2-hour timer keep running if my screen turns off?
The countdown itself stays correct, because it is based on the end time. While it runs, the page asks the browser to keep the screen awake where supported; if the device sleeps anyway, the alarm sounds when it wakes.