- Why are there 12 months in the year, 60 minutes in an hour etc?
- Why isn’t the earliest sunrise on the longest day and the latest sunrise on the shortest?
- Which years are leap years? When was the first leap year?
- What are (my) latitude and longitude?
- What is a meridian? What is the Prime Meridian?
- When and where did the new Millennium officially start, and why?
- Is noon 12 a.m. or 12 p.m.?