They'll be tired after that.
I expect they'll want to put the kettle on, and orient their feet gravitationally.
Two cosmonauts successfully completed a six-hour spacewalk around the International Space Station (ISS), captured on their helmet cams, at 22.46 GMT last night. Flight Engineers Oleg Kononenko and Anton Shkaplerov were busy with a number of housekeeping tasks, including moving the Strela-1 crane from the Pirs docking …
Yeah, six hours sounds about right.
I've seen longer, though, on the Shuttle; I remember one that ran nearly eight hours, pretty much a full working day outside. I try to watch 'em whenever they're on; that really long one started around 7:30am or so EST, about the time I was having my first cup. I logged off the stream after a while when things got boring and nothing really interesting was happening and I needed to get some work done, came back after lunch around 2pm or so, and they were still out there.
The crewmembers' POVs from the helmet cams really make it for me, really gives you a feel for what it's like to be out there. Shame they didn't have those little cams during Apollo; would've been really cool to see what those guys were seeing as they came down the ladder.