The last time someone made me deploy on a Friday was the last time I ever did. I quit that weekend and went back into consulting after things broke (it was also my first week on the job at that company, and their entire IT department thought my manager was crazy).

I’m sure there are cases for it, but I adopted a hard rule that I don’t deploy when there won’t be someone around to fix whatever might go wrong — regardless of what day it is. Call it a personal preference I guess.