2.15. A man rides into town on Friday. He stays one
night and leaves on Friday. (KK)

2.15 answer: Friday is a horse.

2.15 variant answer: The town is near the north pole. Night lasts six
months. (FF)

2.15a. Variant with the same basic gimmick: A woman comes home, sees
Spaghetti on the wall and kills her husband.

2.15a answer: Spaghetti was the name of her pet dog. Her husband had it
stuffed and mounted after it made a mess on his rug. (Simon Travaglia