I don't have any exclusive personal keys so I don't have anything else to attach this thing to.
It is quite handy though. It's a rotating calendar that can tell the day and time of the week up to 50 years.
Particularly, this one I have stops on the year 2056.
https://steemit.com/keychaincontest/@agneslaczo/contest-1-show-me-your-keychain-win-sbd