I'll post this here as a more appropriate forum.

Have a trip from the US to Denmark, will check in with UA (domestic + another *A carrier international, but I am guessing UA agent will do the document check). Passenger's passport expires more than 3 months from the return ticket date, but less than 6 months from the departure date.

My reading of various Schengen area info and Timatic suggests that "3 months from the return date" is sufficient. But - what does UA think? Anyone with experience/insight - would very much appreciate it.