Some companies use divisor 30 for all calculations related to payroll, that is, they take into account that each month has 30 days.

A problem arises in those months that have more or less than 30 days. For months that have 31 days, for example, you must multiply the daily wage value by 31 to obtain the monthly wage. For months that have less than 30 days, you must multiply the daily wage value by 28 or 29. In both cases you obtain different results.

• $400 / 31 = $13 per day (rounded value)

• In February (supposing that February has 28 days), the daily value of the salary is:
• $400 / 28 = $14 per day (rounded value)

For February this means that, compared to months with 30 days, you pay one or two days more; and for months with 31 days, one working day less.

As such, if you consider that every month has 30 days you must "adjust" each month so that the same evaluation criteria apply to all of them.

Where there are absences in the current month you must decide whether this adjustment applies to all the days worked or only to the absences. For example, in January, you pay one working day less or one day of absence less. You must also decide whether to adjust the paid or unpaid leave for the month in question.

Where an employee has been certified unfit or fit to work in the middle of a month, you adjust the non-active days.

In the case of vacations paid in advance, there is no adjustment: these vacations are paid before the employee takes the vacations and the payment is neither reduced or increased.

The payment of absences due to industrial accidents or diseases is processed in the same way: there is no adjustment.

Parameter 30 was incorporated into the ARPRO function of the ARPR subschema to identify whether the company uses the divisor 30 for all of its calculations for the main schema of AR00 payroll.

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