We work Sunday to Thursday, which means the WORKDAY(), WORKDAY_DIFF() isn’t terribly useful. Trying to calculate staff PTO days, but since I can’t figure out how to reconfigure the WORKDAY calculation, staff can’t log time off for a Sunday, for example.
Not sure if this will help, but I ran into a similar problem when working on my PTO base and needed to include Saturdays in the calculation. @Tyler_Kurlas helped me with a formula to find out how many Saturdays were inside a given time frame; you may be able to adjust it for Sundays (I would play around it with but am about to run out for a bit, might have time later)!
Post below shows formula broken down in detail