Setting custom date ranges in Crystal Reports

With George on deployment with the Minnesota National Guard, I'll be occasionally posting on various reporting topics. 
Recently, I had to develop a report which was to return data within a particular date range.  Specifically, a user would need to select a date and the report would then return data from a range of Monday of the previous week to Friday of the current week.  I was able to accomplish this fairly easily using Global and Local variables and a couple of different date functions.
Basically, I needed to get the day of the week for the date selected, and then add or subtract days as necessary to come up with an appropriate number to use with a DateAdd function. All this is done in the record selection formula for the report:

Global DateVar sStartDate; Global DateVar sEndDate; Local NumberVar nDayOfWeek := DayOfWeek({?Date}); //Determine the Day of the week selected. Local NumberVar nAddStart; Local NumberVar nAddEnd; //Determining the number of days to add to the Start Date If nDayOfWeek = 1 Then nAddStart := -6; If nDayOfWeek = 2 Then nAddStart := -7; If nDayOfWeek = 3 Then nAddStart := -8; If nDayOfWeek = 4 Then nAddStart := -9; If nDayOfWeek = 5 Then nAddStart := -10; If nDayOfWeek = 6 Then nAddStart := -11; If nDayOfWeek = 7 Then nAddStart := -12; //Determining the number of days to add to the End Date //(Note, Start and End date have to be done in separate If..Then blocks, otherwise it will not work) If nDayOfWeek = 1 Then nAddEnd := 5; If nDayOfWeek = 2 Then nAddEnd := 4; If nDayOfWeek = 3 Then nAddEnd := 3; If nDayOfWeek = 4 Then nAddEnd := 2; If nDayOfWeek = 5 Then nAddEnd := 1; If nDayOfWeek = 6 Then nAddEnd := 0; If nDayOfWeek = 7 Then nAddEnd := -1; //With the number of days to add/subtract to both dates determined, I use the DateAdd function to return the correct //Start and End Dates sStartDate := Date(Year({?Date}), Month({?Date}), Day(DateAdd('d', nAddStart, {?Date}))); sEndDate := Date(Year({?Date}), Month({?Date}), Day(DateAdd('d', nAddEnd, {?Date}))); //Finally, I use the new dates in the selection criteria. {History.completeddate} >= sStartDate and {History.completeddate} <= sEndDate

Pretty straight-forward, I think.  Depending on your situation, it would just be a matter of figuring out your range and what values to add or subtract to the current date value.