I have two questions about the Entertainment discount. I hope someone can help me.

The Entertment discount is not available on Northwest or Continental on Sundays (or on Fridays during the summer). I don't see any such restriction on the "official" description above - can anyone confirm that you can use this on Sundays? Also does United apply any blackout dates?

Also I'm curious about the requirement that the markets be served by CO or NW. Durango (DRO) is served by CO; Madison (MSN) is served by NW and CO. However neither NW nor CO publishes a fare between MSN and DRO. Will United let me use this for a MSN-DRO ticket?