20 Hour Timer

The Ultimate Day a 20 Hour Focus Timer representing the absolute outer edge of human sustained performance.

✓Free to start

✓No credit card required

✓Takes 5 seconds

✓4.8 ⭐⭐️⭐️⭐️ on Appstore

Your Basic Timer

20:00:00

Click the ring or hit ▶ to start · Space bar works too

This is just a basic timer. Want tasks, ambient sounds, Pomodoro sessions and focus stats on your phone?Download Blazetimer 🚀

What is a 20 hour timer

The 20-hour timer marks the threshold where sleep deprivation research consistently documents impairment equivalent to a blood alcohol content of 0.08% the legal driving limit in most countries. It is also the duration Tim Ferriss identified in The 4-Hour Chef as the minimum immersion required to reach basic competency in any skill through maximum-intensity practice. Navy SEAL Hell Week operates on a 20-hour active-to-4-hour rest cycle, making this duration one of the most tested limits of human endurance. This timer exists for the extraordinary, not the routine.

What people use a 20 hour timer for.

🎯

The Ferriss Competency Block

Tim Ferriss documented that 20 hours of maximum-intensity focused practice is sufficient to reach basic competency in almost any skill. Use this timer for an extreme skill acquisition sprint.

💪

Hell Week Rhythm

Navy SEAL Hell Week operates on a 20-on-4-off schedule. This timer represents one complete active cycle used for understanding your personal limits and building extreme mental resilience.

💻

The All-Night Build

Some of the most important pieces of software, creative works, and business plans were completed in 20-hour all-night sessions. This timer documents and structures the full scope.

🏊

Extreme Endurance Record Attempt

200-mile cycling events, 24-hour track runs, and channel swimming attempts all fall within the 20-hour performance window for elite athletes.

👨‍🍳

Complete Culinary Mastery Immersion

A 20-hour intensive culinary day from 4am market to midnight cleanup covers the complete scope of professional kitchen work and produces more culinary skill development than weeks of standard practice.

🌅

The Annual Maximum

Once per year, by choice and with full preparation, a 20-hour day reveals your absolute capacity. It recalibrates what feels hard, making every future challenge seem more manageable by comparison.

You're using a basic timer.Blazetimer is a focus system.

Stay on this page

Basic browser timer

✓Simple countdown timer
✓Start, pause, reset

🚀 Blazetimer PRO

Blazetimer PRO

✓The Full Focus System
✓Pomodoro sessions (25 min + breaks)
✓Task manager + GTD inbox
✓Ambient sounds, rain, white noise
✓Focus stats + daily charts
✓Live Activities + Dynamic Island
✓Home screen widgets
✓Works offline. Always in your pocket.

3 things a browser timer
will never do.

🎓

Live on your lock screen

Blazetimer uses iOS Live Activities to keep your timer visible on your Lock Screen and in the Dynamic Island. You never have to unlock your phone to check the time.

💼

Knows your timing

A browser timer has no idea why you're timing 2 minutes. Blazetimer ties every session to a task — so you build a real record of where your time goes.

🧠

Builds focus over time

Every session you complete in Blazetimer adds to your focus stats. You can see your daily, weekly, and monthly focus time grow.

They started with a
browser timer too.

⭐⭐⭐⭐⭐ 4.8 rating on the App Store

As someone with ADHD, this is the first productivity app that actually works for me. The visual timer and automatic breaks mean I don't have to make decisions — I just start and the app takes care of everything

Sarah KGraduate student

I've tried every Pomodoro app on the market. Blazetimer is the only one that combines a proper timer with real task management. My work output has genuinely doubled since I started using it.

Marcus TSoftware specialist

The strict mode is a game changer for me. I used to stop my timers constantly when things got difficult. Now I can't and it's taught me that I can actually push through. My exam scores have improved

Aisha OMedical student

Need a Different
Countdown?

All free. All instant. Or download the app for all of them in one place.

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You've been using a Stopwatch. Try a Focus System.

Blazetimer combines your timer, tasks, sounds, and stats in one app designed for people who actually struggle to focus.

✓Free to download

✓No ads ever

✓iPhone · iPad · Apple Watch

✓iCloud sync included