From the archive
Tuesday, 18 August 2026
The expiry date isn't stored anywhere — you build it from a purchase date and a length in months.
You run the returns desk at a hardware store. A customer wants to know if their drill is still under warranty, but the file only has the purchase date and how many months of cover it came with — nobody stores the expiry date itself. Work out the expiry date for each item in column D.
A new exercise every morning, plus every day that came before it — a back catalogue that grows by one a day, whether or not you were here for it.
The last 14 days. Today's challenge is free while your streak is alive; Pro opens every past day too.