Calculations
These calculations are used:
- Comparison of a clock with MAX_ON_TIME: 
           previous_clock_time + MAX_ON_TIME = time_to_compare
- Adjusted clock time: 
           off_clock_punch + OFF_CLK_ADJ_MIN = adjusted_clock_time
- Difference between end of schedule and adjusted clock time: 
           adjusted_clock_time – schedule_end_time = scheduled_end_time_difference