Revising duration so it doesn't count first day
I want the range of days from Monday the 1st to Monday the 21st to read 21 days; yet it reads "22 days" in the duration column. This is because day 1 is the first day, when I need "day 1" to be the following date from the first day. Is there any easy way to fix this? In my job I can never count the first day as day one as it's against policy in how we count days.