Convert hours, minutes and seconds to hours in decimal format.
dh = h+m/60+s/3600 where dh is the decimal hour amount h the hours m the minutes s the seconds
12 hours 36 minutes 12 seconds
dh = 12 + 36/60 + 12/3600 12 + 0.6 + 0.00333 = 12.603333
12 hours 36 minutes 12 seconds = 12.603333 decimal hours