How are the days relating to right ascension around a polar star chart decided?
The date on the charts shows the meridian (north south line) at 8pm local time on that date.  Over a period of a month, the RA of the meridian will move 2hr (so that it gets back to where it started from after 12 months), and hence over 16 days, as you ask about, it will move 1.05 hours.  So you can either say that's close enough to 1 hr, or worry about the small discrepancy - that's assuming the 1hr you cite is actually 1.00hrs.