We have a stop over in Atlanta, 20.20 scheduled landing. Departure 22.59. Lounges close at 22.00 (still find this strange), is there a lounge open longer (or somewhere where the children can relax)?

A17 and B18 lounges are open until 22:30. Most others close at 10. But just to be clear, you are talking about a 59 minute window of not being able to be in the club? How much more time do you want? Boarding begins 40 minutes prior to departure. So now you are down to 19 minutes. Depending on the club you are in and the gate you depart from, that could take 5 - 20 minutes anyway. Which leaves you with 4 to 0 minutes to be at the gate. Besides, it's 10pm, the kids should be exhausted. It's really not that big of a deal.

As Patrick mentioned 22.30 is the latest for Skyclubs at ATL. You will likely land early so might a 5 to 10 min to grab a snack. I like the A17 club better than B18 depending on your gates.

Thanks all! Indeed, becausebof the children, tired for sure, we would like to give them (and us..) some time to relax.

Not in the Airport at that hour.