Questions about the road rate

I made a new goal and converted it to YBHP, the rate is 0.16 hours a day and there’s a 7 day delay from the beginning.
I chose the 0.16 since 10 minutes of 60 minutes are 0.1666666667 hours. Thus, 0.16 hours should be 9.6 minutes.
Beeminder, however, says that 11 minutes will be due eventually. Where does that difference come from?