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.
Light itself takes 4.6 hours to travel from the Earth to Pluto. If you wanted to send a signal to Pluto, it would take 4.6 hours for your transmission to reach Pluto, and then an additional 4.6 hours for their message to return to us.