The employer shall calculate COP using the period of time and the weekly pay rate.

The pay rate for COP purposes is equal to the employee's regular “weekly” pay (the average of the weekly pay over the preceding 52 weeks).

The pay rate excludes overtime pay, but includes other applicable extra pay except to the extent prohibited by law.

Changes in pay or salary (for example, promotion, demotion, within-grade increases, termination of a temporary detail, etc.) which would have otherwise occurred during the 45-day period are to be reflected in the weekly pay determination.

The weekly pay for COP purposes is determined according to the following formulas:

For full or part-time workers (permanent or temporary) who work the same number of hours each week of the year (or of the appointment), the weekly pay rate is the hourly pay rate (A) in effect on the date of injury multiplied by ( × ) the number of hours worked each week (B): A × B = Weekly Pay Rate.

For part-time workers (permanent or temporary) who do not work the same number of hours each week, but who do work each week of the year (or period of appointment), the weekly pay rate is an average of the weekly earnings, established by dividing ( ÷ ) the total earnings (excluding overtime) from the year immediately preceding the injury (A) by the number of weeks (or partial weeks) worked in that year (B): A ÷ B = Weekly Pay Rate.

For intermittent and seasonal workers, whether permanent or temporary, who do not work either the same number of hours or every week of the year (or period of appointment), the weekly pay rate is the average weekly earnings established by dividing ( ÷ ) the total earnings during the full 12-month period immediately preceding the date of injury (excluding overtime) (A), by the number of weeks (or partial weeks) worked during that year (B) (that is, A ÷ B); or 150 times the average daily wage earned in the employment during the days employed within the full year immediately preceding the date of injury divided by 52 weeks, whichever is greater.