Technical process:

1. Set target: User sets duration (e.g., 10 minutes = 600 seconds)
2. Start time: Timer records current timestamp
3. Calculate remaining: Every second, calculates: Target - (Current - Start)
4. Update display: Converts remaining seconds to HH:MM:SS format
5. Check completion: When remaining ≤ 0, trigger alarm

Implementation: Uses JavaScript `setInterval()` to check time every 1000ms (1 second). More accurate than decrementing a counter because it self-corrects for JavaScript execution delays.

Yes, but with considerations:

• ✅ Timer continues: Countdown runs in background tab
• ✅ Alarm sounds: Audio plays even if browser is minimized
• ✅ Accurate timing: Uses system clock, not affected by minimizing
• ⚠️ Tab must stay open: Closing tab stops timer
• ⚠️ Browser throttling: Some browsers slow background tabs to save resources

Best practice: Keep browser window open (can be minimized) for important timers. For critical timing, use multiple timers as backup.

Key differences:

This tool has both! Switch between Timer and Stopwatch modes using the tabs at the top.

Accuracy: ±1 second under normal conditions

Factors affecting accuracy:

• System clock: Timer syncs with your device's time - if system clock is accurate, timer is accurate
• JavaScript execution: Minimal delay (~1-50ms) typically unnoticeable
• CPU load: Heavy system load can delay updates by 100-500ms
• Browser throttling: Background tabs may update less frequently

Why it's reliable: Uses `Date.now()` to calculate elapsed time, not simple countdown. Self-corrects for execution delays. Good enough for cooking, workouts, productivity - not for scientific precision timing.

Yes! Up to 99 hours, 59 minutes, 59 seconds

Long duration examples:

• 1 hour: 01:00:00 - Standard work blocks
• 8 hours: 08:00:00 - Full work day
• 24 hours: 24:00:00 - One full day
• 72 hours: 72:00:00 - 3-day event countdown

Use cases for long timers:

• Slow-cooking recipes (6-8 hours)
• Fermentation processes (24-48 hours)
• Event countdowns (days to deadline)
• Project milestones

Note: For multi-day countdowns, ensure device stays on and browser tab remains open.

No. Alarm respects system volume.

Volume requirements:

• System volume: Must be above zero
• Browser permissions: Audio must be allowed (usually automatic)
• Tab audio: Ensure tab isn't individually muted (check speaker icon on tab)

Testing alarm:

1. Set a 5-second timer
2. Enable "Alarm sound" checkbox
3. Click Start and wait
4. If no sound, check volume settings

Alternative alerts: Even without sound, the screen flashes red when timer completes, providing visual notification.