Approaches to show/performance schedule information in RSS

[John F. Pries <jfp@audibilities.com>]

We are currently serving RSS of internet radio show schedule 
information in .91 and would like to better understand how RSS viewers 
(client or server like yahoo) prioritize and age item information.

The item url is static (across showtimes of a particular show), and 
we're changing the item title and item description to include 
descriptive showtime information (such as, the show is live now, or the 
next scheduled time).

The behavior we desire is to have the most recently updated (ie. live 
now) shows on top, and the upcoming shows, ordered by start time, 
further down the list.  We create the rss file in this order.

Some viewers seem to have different behavior in how the "updated" 
showtime items are displayed.  Yahoo is an extreme case where items too 
far in the future seem to "expire" (before it's showtime) since neither 
the title, url, or description change.

Is reader behavior different? Is there a trove of knowledge on reader 
behaviors in this area?  More importantly, is there a generally 
accepted approach to deliver schedule like information in RSS? In .91?

a sample feed is:
http://www.radioshowlinks.com/rss.aspx?id=11

thanks in advance for any guidance ... and excuse me it this is the 
wrong group ...

Regards.

John