Comment by schiffern
In the official BIPM brochure, hours are technically classified as "Non-SI units accepted for use with SI." This puts them in the same category as liters, hectares, tonnes, decibels, etc.
https://en.wikipedia.org/wiki/Non-SI_units_mentioned_in_the_...
I can read Wikipedia too. All the calculations are done in m, s, g, etc. if you want to dumb it down to the public you might as well go in miles per hour, leagues per day, etc., spaceflight is not the place where it is appropriate.