Where the 4 hour each day missing??

Our 24 hour time system have 24 hour per day.
But my 20 Hie time System only have 20 Hie, where the 4 hour goes???
Actually i already convert the 4 hour into the 20 Hie.
One Hie is equal to 72 minutes or 1 hour and 12 minutes.
That is why there are 4 hour look like missing but actually i already mix it equally into each Hie time.
Anyone want to ask any question???