I had telecommunication PBX cutover projects that would have to be completed on Sunday evening for one of the biggest retail stores in the U.S.A . Sunday the store would close earlier than most other days giving the team more hours to complete the go live time before Monday morning when business would open back up again. At this point most of the communications would be operational and for the most part minor issues could be addressed during regular working business hours.

So i guess it depends on the business or situation or quiet time as Ian addressed.

Main MDF room looked like this with a bunch of techs, others in the room working sometimes for about 24 hours strait.