12. The report must be sent to the Commission not later than the 15th day of each month; it covers the previous monthly working period.
The employer must send a report for every monthly period of work, whether work was performed or not by himself or his employees.
The monthly period of work must consist of not less than 4 and not more than 5 weeks, and must end on the last Saturday of the month. A monthly period begins on the Sunday following the last day of the previous monthly period.
The working week begins at 12:01 a.m. on Sunday and ends at 12:00 p.m. on Saturday.