Broadcasts that span multiple days?

I’m cleaning up the A State of Trance series and for #400 they did an event called “72 Hours Radio” which was literally 72-hour back to back set containing mixes from dozens of DJs (ignore the titles, I had to merge each hour from separate release groups):

My question is, since this spans multiple days should they be split into 3 separate release groups with the date of each or should it be one release group and use the date as the start of the broadcast?

I realize this is a pretty extreme case, but I can also see how a lot of broadcasts/DJ sets that span over midnight would have the same problem. Personally I think because it’s one continuous broadcast it should be treated as a single release group because it’s one continuous stream. Maybe we should use relationships to describe the recording date?