Countdown to any event, use a precise stopwatch, run Pomodoro sessions, decode Cron expressions, and calculate optimal sleep/wake times.
All processing happens locally in your browser — timers run in real-time, no data uploaded.
00:00:00
Set a target time to start countdown
00:00:00.0
Ready
25:00
Focus Session 1/4
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No alarm set
Countdown: Set a target date/time and watch the countdown in real-time. Preset buttons for quick setup.
Stopwatch: High-precision stopwatch with lap timing. Measures to 1/10th of a second.
Pomodoro: Configurable focus/break timer. After each focus session, auto-switches to break. Long break after every N sessions.
Cron Parser: Decode standard 5-field Cron expressions and see the next 5 execution times.
Countdowns, stopwatches and drift
A countdown counts the time remaining to a fixed target moment; a stopwatch counts the time elapsed since it started — the same clock read in opposite directions. Pomodoro is just a preset rhythm of countdowns: 25-minute focus sessions with short breaks.
Ticking timers drift — a setInterval scheduled every 1000 ms actually fires a few milliseconds late each time, and the error accumulates — which is why reliable timers re-read the real clock (Date.now() difference) instead of counting their own ticks; over an hour, naive tick-counting can run seconds fast or slow.
