Originally Posted by jrobin

I am booking a return flight ORD-YYZ with a connection in BOS.
On an early search I was offered an overnight connection in BOS on the return trip.
I later decided I would prefer that, but now when I search, the overnight connection is not offered.
I tried searching "All day", "evening" but no luck.
I tried Google flights, but also no luck.
Are overnight connections offered randomly?
Is there a search procedure to increase the chance of being offered an overnight connection, either on AA or elsewhere?