Doomsday Practice App Icon

Doomsday Practice

Train your weekday mental math, one date at a time

iOS App Coming Soon

Features

🗓️

Random Date Challenges

Practice with fresh dates every round and choose the weekday from a clear 7-day answer grid.

⚡

Instant Feedback

See right away if you were correct, with clear highlighting of your pick and the right answer.

🧠

Learn Mode

Follow guided, step-by-step drills that teach the Doomsday method in a practical way.

📈

Progress Tracking

Track streaks, accuracy, daily progress, and speed trends so you can see improvement over time.

🎯

Daily Goal Motivation

Set a daily practice rhythm and unlock milestone progress banners as you move toward your goal.

🔒

Private by Default

Your stats and settings stay local on your device. No account creation required.

How to Use

Play a Round

1

Read the Date

Start a new challenge and look at the date shown on screen.

2

Pick the Weekday

Tap the weekday you think matches the date.

3

Review the Result

Get instant feedback and see the correct answer highlighted.

4

Continue Training

Tap "Next Date" to keep practicing, or open "Review" after a miss to understand why.

Tip: If you want faster sessions, enable Auto-Advance in settings so the next challenge appears automatically after each answer.

Improve Your Skills

1

Use Learn

Open Learn mode for guided practice on century anchors, year anchors, month anchors, and counting.

2

Use Review After Mistakes

When you miss a question, open the Review sheet to see a worked explanation of the path to the answer.

3

Watch Your Trends

Use your profile stats to monitor consistency, speed, and accuracy over time.

Frequently Asked Questions

Doomsday Practice helps you build speed and confidence at finding the weekday for any date using mental math. It is designed for daily repetition with immediate feedback.
No. You can start directly in Learn mode and follow the guided steps. The app is structured so beginners can build from fundamentals, while experienced users can jump straight into practice rounds.
Your answer and the correct weekday are clearly highlighted, and you can open a Review sheet that explains how to calculate the result.
Yes. The app tracks daily activity, streaks, accuracy, and response-time trends so you can measure progress over weeks and months.
Yes. You can enable round timing and run timed sessions. When active, correct answers can record response times for your stats.
Yes. In settings, you can adjust the year range to practice across different eras while keeping a minimum span for variety.
Yes. A reset option is available in settings if you want a fresh start.
No. Core gameplay and your saved progress work locally on your device.

Contact & Support

Need Help?

If you have questions, feedback, or run into any issues, I'd love to hear from you.

feedback@taiyotsuchiya.com

Privacy Policy

Last updated: April 2026

No Personal Data Collection

Doomsday Practice does not require an account and does not collect personal information.

Local Storage Only

Your settings and progress are stored on your device. This data:

  • Stays on your device
  • Is not sold or shared with third parties
  • Is removed when the app is uninstalled

No Ads or Tracking

Doomsday Practice contains no ad network SDKs and no behavioral tracking.

Contact

If you have any questions about this privacy policy, please contact feedback@taiyotsuchiya.com