Dan Q posted a note for GC3D6J8 The Leap Year Club

This checkin to GC3D6J8 The Leap Year Club reflects a geocaching.com log entry. See more of Dan's cache logs.

Enjoyed solving this puzzle, although possibly not 100% in the way the author intended (I spotted some mathematical quirks that gave me a shortcut/cut down the number of possibilities for matching first and surnames!). Now I just need to find an excuse to get over to the GZ and find it! (No idea how soon that’ll be, though!)

Solving this puzzle cache was inspired by a conversation on the Geoleaks forum.