Summarize (?!)/signify change in a field

[zaphod]

I don't even know what to call what I'm trying to do so here it is--

I have a portal that lists records sorted by 'due date'

What I want to do is have some distinguishing feature (i.e. a line or symbol) to show when there is a change of date in the list.

an example would be:

4/1/01

4/1/01

------

5/3/01

-----

6/1/01

6/1/01

Is there anyway to do this, any terminology that might help me in solving this?

Much thanks ahead of time.