This sundial ring has a cool history

Legend has it that this is a replica of a ring given by Elenor of Aquitaine to Henry II.

He dug it so much he had one made with a ton of diamonds and the words "Capre Diem" (Seize the Day) engraved in it for her

.Either way, this is kinda cool. 

There is a slider where you set the month.

 When held by the string, the sun casts a bright spot on the time.