If you would like to match each time with a time above, you can do this using the following steps:
a 3h 18m 7s = 11887s
3h = 3 * 60m = 180m;Â 180m + 18m = 198m;Â 198m = 198 * 60s =Â 11880s;Â 11880s + 7s = 11887s
b  8300min = approximately 5 days 18 hours
8300min = 8300 * 60s =Â 498000s
8300 min / 60 min = 138h 20min; 138h / 24h = 5 days 18 hours 20min
c 1461 days
1461 days = 1461 * 24 hours =Â 35064 hours
d 44640min. = 31 days
44640min / 60min = 744 hours;Â 744 hours / 24 hours = 31 days
e 10:21:2.5
10:21:2.5 = 10 hours, 21 minutes, 2 seconds, 50 milliseconds