http://www.perlmonks.org?node_id=1227661


in reply to Date::Manip how to set FirstDay to Sunday

Hi Lena2018!

Your workdays seem to be special :-)

In Date::Manip::Config it says under BUSINESS CONFIGURATION VARIABLES:
… WorkWeekBeg must come before WorkWeekEnd numerically so there is no way to handle a work week of Sunday to Thursday using these variables.

To handle a work week of Sunday to Thursday, just set WorkWeekBeg=1 and WorkWeekEnd=7 and defined a holiday that occurs every Friday and Saturday.
… can be done using recurrences. Refer to the Date::Manip::Recur documentation for details.