Interval Alarm

Choose an interval in seconds, minutes or hours, or use a minute preset. Add an optional reminder, then press Start. The first alarm follows one full interval; the display shows the time until the next alarm.

• Intervals range from 1 second to 24 hours. Decimal minutes/hours are allowed if they produce whole seconds, for example 1.5 minutes = 90 seconds. Inputs are never silently shortened.
• The interval and reminder are locked while running. Stop cancels future alarms; a new start begins a full interval.
• Test sound plays one short tone without starting an alarm. Sound controls automatic signals; Start activates browser audio. Device volume and browser mute settings still apply.
• Switching tools on this page keeps the alarm running. After a delayed callback, it signals once and skips missed slots while keeping the original cadence.
• Reloading or closing the page stops the alarm; only input drafts and the sound preference are restored. Browser suspension or device sleep can delay or prevent sound. Timing follows the device clock. This is not a system alarm.