5 months * 4.3 weeks * 7 days * 24 hours = 3612 hours
3612 hours / 75 years / 365.25 days = 0.1319 hours per day.
60 * 0.1319 = 8 minutes per day.
That is remarkably close for the majority of the population using canned goo and carts or electrics.
Heck... I headshave with a cart and straight shave my face... all in the shower, and take about 1/2 hour for everything.
The face shave might add 10 minutes to the shower.