1 day (0) -> 9 hrs
2 days (1-5) -> 18 hrs
3 days (6-10) -> 1 day 3 hrs
4 days (11-15) -> 1 day 12 hrs
5 days (16-20) -> 1 day 21 hrs
6 days (21-25) -> 2 days 6 hrs
7 days (26-30) -> 2 days 15 hrs
8 days (31-35) -> 3 days
9 days (36-40) -> 3 days 9 hrs
10 days (41+) -> 3 days 18 hrs