I don't know. Why do we push files to production on a Friday evening? Why do we snipe hot-fixes into production via FTP? Because we are all crazy & lazy bums, I would guess.
Because we worked for the whole week on it and now want that other people can see it on their weekend. Since we are so proud of our work and trust in its quality, we are willing to do an extra shift on the weekend, should problems occur.
The experience which gave me perspective was on a project at my previous job. I worked together with another highly passionate engineer and we made amazing progress over the course of a very short time.
The day before the demonstration of our results to our bosses, meant to serve as evaluation and retrospective for this project, we had reached all goals and the simulation was really robust and stable. However, when I came to work on the day itself, I found my colleague sitting at his desk, looking very tired. He'd been working through the night to get all the extra bells and whistles implemented. The demonstration was a disaster. Nothing worked, everything crashed. A lot of people were upset.
Simile. Or analogy, perhaps.
... Is that kind of pedantic correction a sign of unlikable intelligence? :P
You also didnt ask what could prompt before weekend pushes. It could be money, reputation or or compliance. Certain projects are out of your control and you have to implement in weeks notice, or have a deadline imposed by laws. Some are losing revenue so each day you do not release you are bleeding money.
So please, by all means, take your weekend off, while i plan for worst cases and make it so that friday releases are "trivial and safe" to deploy. I do not have to use it, but if i do, i do not need you around, it will be mostly automated anyway.
If you work weekends then by all means push on Friday evening. However, don't push anything the before your next vacations.
:p
I dont do friday releases often, but if it comes to it, it is no brainer. I approach it pragmatically, and this helps people.