Doomsday Trainer

Inefficient Code

About this game

Have you ever wanted to instantly know what day of the week you were born on? Or what day January 1st, 2050 will fall on?

With the famous Doomsday Algorithm, you can calculate the exact weekday of any date in history using just mental math—and Doomsday Trainer is the ultimate arcade-style app to teach you how to do it.

Whether you want to sharpen your mind, practice mental arithmetic, or just learn an incredible party trick, this app provides everything you need to master the calendar.

CORE FEATURES:

🧠 Training Mode
Don't know the math yet? No problem. Training Mode breaks the algorithm down into bite-sized, learnable steps. If you get stuck, use the built-in hint system and integrated Leap Year rules to guide you to the right answer.

⏱️ Game Mode
Once you understand the formula, it's time to put your brain to the test! Race against the clock, build massive correct-answer streaks, and set new personal high scores.

🎯 Custom Mode
Want to drill a specific era? Choose a custom date or set a year range to focus your practice exactly where you need it most.

📈 Progress Tracking
Follow your improvement over time with streak records, speed records, and progress charts showing your accuracy and speed across the last 6 months.

🌍 Google Play Leaderboards
Compete globally — your best streaks and fastest answers are submitted to Google Play Games leaderboards so you can see how you stack up against players worldwide.

👾 Retro 8-Bit Aesthetic
Mental math doesn't have to be boring. Choose from multiple themes including a classic green-screen terminal look, a clean light mode, and a sleek dark mode — all with a minimalist arcade feel.

🎵 Atmospheric Soundtrack
Get in the zone with an optional background theme that sets the perfect mood for mental calculation.

🌐 No Ads, No Forced Accounts
No internet required to play, no intrusive ads, and no forced sign-in. Google Play Games is optional and only used for leaderboards and cloud saves.

Download Doomsday Trainer today, master the algorithm, and become a mental time traveler!

What’s new

Welcome to Doomsday Trainer v4.9!