Calendar puzzles — Maths Olympiad practice

How to solve it

Throw away the weeks — “only the days left over after whole weeks move the day of the week”

1. Count the days between the two dates (use the month lengths: 30 or 31, February 28 in an ordinary year).
2. Divide by 7: whole weeks do not change the day; the remainder does.
3. Count the remainder on from the starting day.

Use it for: Day-of-the-week puzzles, birthdays, holidays and “after 100 days” questions.

Worked example: If 5 March is a Tuesday, what day of the week is 23 March? Saturday

✏️ Practice

Work it out on paper, then tap the answer you think is right. Stuck? Press “Show me how” to see every step.

🏁 Topic 12 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 📅 Date Puzzle Pro badge when you pass — and a certificate when you finish all 7 topics of Part 2 · Class 5–7. You can still take the test without signing in.

🖨️ Calendar Worksheet for Maths Olympiad

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)