Plot Date Interval

[deleted_user]

Hello,
I have data on days individuals perform an activity set up as follows:

Individual Start Date End Date Total Days
1 10/15/2005 10/18/2005 4
2 11/7/2005 11/30/2005 23
3 12/1/2005 12/2/2005 2

I would like to create a plot where along the x axis we have consecutive days and along the y axis the date interval the activity is being performed. For each individual we would have a response of 1 on dates the activity takes place and 0 when it doesn't, then sum across all individuals for each day. That is, if 20 individuals are active on 11/7, then the y-value is 20 etc. Unfortunately, I am having trouble getting the data set up in a way to do this. Does anybody have any suggestions?

[GraphGuy]

This graph isn't exactly what you're asking for, but I think it might be a good way to display data like yours...

http://robslink.com/SAS/democd18/float2.htm

http://robslink.com/SAS/democd18/float2_info.htm