This is a simile which makes the reader think about how long it's taking for the hours to go by.
Wise beyond his years
there are 192,720 hours in 22 years, not counting leap years. counting leap years there are 192,840 hours.
Disregarding the leap years, 17598840 hours Regarding leap years, about 17610888 hours
there are 613200 hours in 70 years. there are 8760 hours in one year. Except for leap years, which comprise 8,784 hours.
18 years = 157,784.63 hours.
89 years = 780,157.337 hours
20 years is 175,200 hours
40 years = 350,632.5 hours.
6,324 hours = 0.721439091 years.
555 years is about 160,545,960 hours.
Three years is about 26,297.43 hours.
10 years = 87,658.1277 hours.