There have been some threads on this -- I thought you had to claim the bags if the layover was greater than 12 hours but I may be misremembering it (it is is the CoC) I often do a "23 hour layover" in Atlanta and once last year on my way to LHR I had bags to check. I asked if they could check them thru and they did, but that may be just a service to a DM.

That being said, there is a place you can store bags -- I think it advertises as a place that wraps your bags but they will store them as well (for a fee, obviously). That was my backup plan last year. It's on the DL side of baggage claim.