There's an old saying "don't buy a car that was built on a Friday". The theory being that the socket monkeys who put the thing together were thinking more about the weekend than your ride and it would have more problems than a car built on another day of the week. So I'm sitting here wrapping up some functionality and doing my testing but I'm really thinking about getting my drink on this evening. Should I deploy my Friday Code or wait until the dark gloom of Monday to roll this code out?
In my case, I don't think it has anything to do with the day of the week, as it is possible to get distracted by anything from exhaustion to waiting for the weekend. I thoroughly test my code, so I feel comfortable with deploying in most cases.
Development, on the other hand, is completely different. I sometimes go in these "bright ideas" directions, that lead to a "what was I thinking?" moment. In those cases, CVS is my friend.