I have done such a problem with a master calender. I define a calender with all dates between yearstart(today-365) and yearend(today+365) and load the date field in the diffrent tables twice. One time with the real name and the other time with a "keyname" which doesn't appear in the report table, but only in the list boxes where you can make your limitation.
See the attached file.
MasterCalender.qvw 176.0 K
Thanks for the response. I started setting something up last night with a button control that did a select from the multiple date fields and that seemed to work. I'll download your example and have a look at that too - I'm sure that your way is better because it just uses 1 calendar control instead of making the user set a day, month and year field like I'm doing at the moment.