Doomsday Method | Mental Game
教育
僅適用於 iPhone
免費 · App內購買 · 專為 iPhone 設計。尚未針對 macOS 驗證。
iPhone
Someone tells you the date they were born. You tell them it was a Monday.
That is a real skill, it takes about a week to learn, and this app teaches it end to end.
The Doomsday algorithm — invented by the mathematician John Conway — turns any date into its weekday using arithmetic small enough to finish while someone is still saying the date. No lookup. No phone. No calendar.
LEARN
48 lessons across 11 chapters, in three parts
178 checkpoint questions. You answer in your head, then check yourself against the worked reasoning — nothing is graded, and nothing is rushed
Interactive calendars, anchor tables and step-by-step walkthroughs inside the lessons themselves
Mnemonics that stick: 4/4, 6/6, 8/8, 10/10, 12/12, and "9-to-5 at the 7-Eleven"
Six different ways to work the year offset. Pick the one your head likes, and every worked explanation in the app is rewritten in it
Seven Extras: why the method works, Easter and the computus, the Julian calendar, Conway's own shortcuts, the record holders, and full reference tables
A cheatsheet with every anchor and every offset on one screen
TRAIN
10 drills: weekday numbers, counting in sevens, leap years, century anchors, the year offset, month doomsdays, day counting, reverse dates, Julian dates and Easter
Five stars a drill, earned by answering cleanly — right, and inside that drill's target time
Nothing cuts you off mid-question, and training never costs you rating
PLAY
Classic — endless real dates, at your own pace, with no clock at all
Daily Challenge — five dates drawn from the day itself, identical for every player on earth, one attempt a day
Time Attack — two minutes, as many dates as you can, ten seconds off for every miss
Choose your range: 2000–2099, 1800–2199, or the whole Gregorian calendar from 1583 to 2599
YOUR PROGRESS
A Doomsday Rating that rises when you are right and quick, and never pays for a guess
Accuracy and speed over time, your rating history, and a 12-week activity calendar
Game Center leaderboards for today's challenge and the global rating, friends included
BUILT PROPERLY
No account, no sign-up, no ads
Works offline
Every number in every lesson is re-derived by a checker that shares no code with the app, so an explanation cannot drift from the answer it gives
Analytics are opt-in, pseudonymous and on EU servers. You are asked once, and can change your mind any time in Settings
Coming from the old Doomsday Method? Your history is imported and replayed answer by answer, so your chart reaches back and your rating arrives honest
Start free. One optional purchase opens the rest — one payment, not a subscription.
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EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
評分與評論
- 此 App 尚未收到足夠的評分或評論，無法顯示概覽。
Thank you for using the Doomsday Method App to learn and play Conway's famous mental math method!
What's new in 2.2:
- Your progress is now backed up to iCloud. Reinstall the app or switch to a new iPhone, and your rating, streak, statistics, daily wins and lessons come back automatically.
- Wrong answers now show your guess next to the correct answer.
- New leaderboard: Daily Challenge Wins. Every day you finish first counts, and on the other leaderboards a small crown shows how many days a player has won.
- Leaderboards now load reliably right after launch.
- Smaller fixes and improvements.
開發者Leon Grimmeisen指出App的隱私權實務可能包含下方描述的資料處理。如需更多資訊，請參閱 開發者的隱私權政策 。
不會與你連結的資料
系統可能會收集以下資料，但不會將其與你的身分連結：
- 購買項目
- 識別碼
- 使用狀況資料
輔助使用
開發者尚未表示此 App 支援的輔助使用功能。 進一步瞭解
資訊
- 供應商
- Leon Grimmeisen
- 大小
- 10.8 MB
- 類別
- 教育
- 相容性
需要 iOS 17.0 或以上版本。
- iPhone
需要 iOS 17.0 或以上版本。 - Mac
需要 macOS 14.0（或以上版本）以及配備 Apple M1（或以上版本）晶片的 Mac。 - Apple Vision
需要 visionOS 1.0 或以上版本。
- iPhone
- 語言
- 英文
- 年齡分級
4+
- 4+
- App內購買
是
- Doomsday Pro $320.00
- 版權
- © 2026 Leon Grimmeisen
