I have done lots of daytrips.
We did 6 hours in NYC recently because my Daughter wanted to see Times Square. We also walked across the Brooklyn Bridge.

I think my craziest ever was LAS-EWR-MIA-CPT-MIA-IAH-LAS on CO, SA, and HP
Was in CPT for just 30 hours.

We did an on the fly once while in ATL, where we had just come back from 3 days in GGT. I still had some time off, so with about an hour before departure, we decided to go to DUB.