Overlapping dates in SPSS? help needed badly!!!

#1
Hi,

I have a very simple database that I need some help with. Using SPSS 15.

Variables: Case_No, Activity1, start_date1, stop_date1, activity2, start_date2, stop_date2, activity3, start_date3, stop_date3...etc...goes on until there are about 7 activity variables and start/stop dates for each.

The activity variable is nominal and lists a type of activity. The stop and start date for each activity indicate when it was stopped and started.

Here's a very simple example from the data:

Activity1.....Start_date1....stop_date1...activity2...start_date..stop_date2
Basketball...9/30/01........10/30/01.......Jogging.....10/1/2001...10/4/2001

I want SPSS to tell me how many days of overlap between the two dates and what the nominal labels are. So this one would spit out:

Activities Occuring Together....Number of Days
Basketball + Jogging.......................3

There HAS to be a way to do this.

Although a solution to the simple issue above would be appreciated, in my actual data there are more than two possible activities...so if there is a solution for 5-6-7 activities, that would be most helpful.

If anyone can help, I would be eternally grateful and I would be happy to send beer, chocolates, sports tickets, or other bribes directly to your street address.

Thanks,

Pete