Despite their similar and sometimes confusing acronyms and their overall purpose of allowing tax-free reimbursement of various types of medical expenses, health savings accounts (HSAs) and health reimbursement arrangements (HRAs) are quite different when you get down to the details.
A full rotation of Pluto takes 6 Earth days, 9 hours, and some minutes; so the day part should be about half that amount (3 days and 5 hours), at least on average.
So low orbits around rocky bodies will be on the order of two hours, regardless of the size. For Earth, $\rho=5.51\,\mathrm{g/cm^3}$, which gives a period of 92 minutes. For the Moon with $\rho=3.34\,\mathrm{g/cm^3}$, the period is 118 minutes.