How do i edit the calendar used in excel calculations

[briancarroll101]

I wish to edit the calendar that excel uses to make calculations. I'm making
a time-line for projected dates for the completion of different actions but
do not want any of these action dates to fall on weekends or public holidays
and during the christmas holiday period

 

[Kevin B]

While you can't modify the calendar directly you can look up the
NETWORKDAYS() function in Excel's help. This calculates elapsed days,
ignoring weekends and you can tell the function what holidays to exclude as
well.