(b) If an employee uses sick leave for a shift that is defined by business needs rather than a set number of hours or for another shift of indeterminate length, the employer may determine the amount of sick leave used by the employee based on a reasonable calculation. An employer shall apply a consistent methodology to calculate the normal hourly compensation of similarly situated employees, including

1. (1) the number of hours worked by a replacement employee in the same shift or a similarly situated employee who works the same shift or who has worked a similar shift in the past; or
2. (2) the average number of daily hours the employee has worked for the last 30 days.