Dear friend,
When the actual attendance of an employee covered by the statutory minimum wages falls short in the whole wage period i.e., a month, he is not entitled to wages for the days of unauthorised absence and his salary has to be calculated proportionately and paid. Certainly such salary for lesser no of days worked would be less than the normal monthly salary. It cannot be treated as lesser payment.
Normally, to arrive at daily wages, the monthy wages shall be divided by 26 and to arrive at the monthly wages, the daily rate shall be multiplied by 30.
If you want to be exactly precise in respect of the month of February which is always less than 30 days, take the total no of days minus the no of weekly holidays in the month.