Villagers got into a bread trading loop where two adults and one baby began throwing bread back and forth for ~5 minutes real time. Sunset may have been the determining factor for ending their loop.
The attached video is only a small portion of the entire activity, but representative of the duration.

This is a creative flat, normal diff, testing world I was using for other villager behavior testing with a 10x10 37 door structure in the center of a fenced off farming region.
At the time there were only 2 adults and 4 children in the region.