An elevator bank monitoring system shows the clock time in hours and minutes on multiple displays. The time is generated by a programmable 16 - bit timer, which uses a 50 - kHz clock signal for calculating seconds. These seconds are then accumulated to minutes and further to hours by software. However, the users of monitors were initially complaining that the clock time is advancing or lagging up to 7 minutes in a month.

A field engineer made a survey of the problem and noticed that the magnitude of advance or lag remains practically constant on each site, but is dependent on the individual monitoring computer. Based on these observations, a solution for the annoying problem was developed and taken in use in the final testing stage before the complete monitoring system leaves the elevator factory.
What kind of approach would you take with this problem if no hardware modifications were allowed? Hint: the monitoring computer has free parameter space in a Flash memory that can be accessed by a service tool.