Code-Golfing Tweet-a-Program: Martin Luther King's age in years and days on other planets if he was living on them! :-)
AssociationThread[{"yr","days"}->(Now-=[King bday])/#]&/@Dataset[PlanetData[All,{"OrbitPeriod","SolarDay"},"EntityAssociation"]]

Interestingly, Martin Luther King would be 364 years old on Mercury but only 182 days old since one solar day on Mercury lasts about as long as 176 days on Earth!