Chris,
The application has to accept overlapping date. While viewing the data, the screen has to split the date & show in the above format.
Actaully i've one more table that has data for each days.

ie in the first table i store
SDate EDate Value
10/10/2002 10/15/2002 15

in the second table i store
date value
10/10/2002 15
10/11/2002 15
...
10/15/2002 15

If the date is overlapped in the first table, the corresponding record in the second table will be replaced with the newly overlapped records.

Hope to get a solution.