To have a common function which would calculate number of working days in a month with month as input.
By giving month name/number as input along with working day offset in so we can select first day of week, from that it should calculate the next five days as working day instead picking Monday as default start of week.
Add regular and incidental non working days lists, to be filled in by implementation.
(example: Friday, Saturday > standard weekly) (thanksgiving, ascension, ganuka... > incidental)