well that's one side of the coin.
you don t have to charge 1/2 or full days ,as long as you charge what ever it takes to service the customer,do the job right and cover the expenses,make a profit etc.
however what happens to the electrician who is dispatched and not in charge of the type of calls,the driving distance,the quality of the calls etc etc?
what if you dispatched to jobs where the driving time already exceeds the time you will bill as billable hr?
what about the efficiency in this case?