Just as an overall note, as xliioper is also pointing out, stopover/layover rules vary by destination (which is also when you post something like "I'm going to XXX-ORD-LAX", it makes it harder to offer advice as that does not indicate if it is a domestic itin, international itin, etc. (And if you are in witness protection, maybe you shouldn't be posting here. That's a joke; I know why people don't want to post specifics, I don't a lot of times either, but if you are vague, again it makes it harder to offer advice cause the reader can't tell what the exact situation is.))

The general rule is that domestic stopovers are limited to 4 hours. International are generally limited to 24 hours. Are there exceptions to these general rules? Yes. Will the online system sometimes balk at booking a longer layover, even if it is allowed? Yes. Will you have some phone agents that will argue against the published rule (for various reasons)? Yes. Did I use softer words like 'general' and not definitive phrases like 'set in stone' on purpose? Yes.