This rule is regulated under French law. If you don't depend on the French law, we advise you to dismiss this column.
In France, how does it work ?
The employees are paid on a monthly basis, i.e. they always receive the same salary, whether the month lasts 29 or 31 days.
In a year, there are 52 weeks for 12 months. So on average, we have 4.3333 weeks per month. This is the magic number for any payroll accountant !
The monthly salary or theoretical contract is an average obtained by multiplying the employee's weekly contract time by 4.3333.
In reality, there are rarely 4.3333 weeks in a month. Your employee will rarely, if ever, work 151.40 hours per month. Yet he will receive the same pay.