If you find yourself in a position where you need to report into the future, Crystal provides a couple of functions that allow you control what data is displaying. 

First lets look at the AllDatesFromToday and AllDatesFromTomorrow functions.  These functions are found under the DateRanges group of functions in the Functions tree found in Crystal Formula Editor.

AllDatesFromToday, specifies a range of Date values that includes any date from the present day to any future Date value that may appear in a field. AllDatesFromToday includes the present day.

AllDatesFromTomorrow, specifies a range of Date values that fall after the present day. AllDatesFromTomorrow does not include the present day, but does include any future date.

The use of these functions are simple enough, the syntax looks something like this.

{ACTIVITY.STARTDATE} in AllDatesFromToday

The functions will provide all records that qualify no matter how far out. 

For this instances where you want to limit how far out you could use functions like one called "Next30Days". There are actually a couple additional functions along the same lines to include Next31To60Days, Next61To90Days, and Next91To365Days.  The syntax looks like this:

{ACTIVITY.STARTDATE} in Next30Days

Have fun reporting.