Contact

An answer looks wrong?

Day length here is sunset minus sunrise on the puzzle’s date, in each city’s local time, calculated for sea level with SunCalc. Weather apps can differ by a minute or two (they may use a different city center, elevation or rounding), but not by the 20 minutes or more that separate neighbors in a puzzle. If something still looks off, include:

• the puzzle number or date,
• the cities involved, and
• where you saw a different time, if anywhere.

Missing a city?

Tell us which one and why it would make a good puzzle. Browse the cities first: the site covers 1,301.

Reporting a bug

Tell us what happened, what you expected, and which device and browser you were using. A screenshot helps.

Partnerships

For sponsorships, classroom use or anything else, write to the same address.