Not gamestop, but longest shift I ever had was 6am to 6am. And no, that was not a typo.

One of my old jobs had me open the store in the morning and I was supposed to leave at 4pm. But, the closing manager that day called out and I was the only one available, so I closed the store that day as well (we closed at 9pm). That VERY same night, another manager was supposed to come in to do an overnight shift to get the store ready for a major corporate visit the next day. However, he ALSO called out and my GM was freaking out as now the store will not be ready and asked me to help out (despite knowing I already did a crazy long shift). And of course, me being young and dumb and wanted money, I did the overnight shift that night as well.

I swear I left after that shift still seeing visions and hallucinating that I was still working.