Whenever a feature or bug fix is done, especially if requested by a client. This includes Friday afternoons, but as weekdays are usually not overloaded, we don't mind. I even remember deploying at 4 AM, and I don't remember being upset about it.

We deploy continuously, but avoid Friday late in the afternoon (before going home).

Well I think I'm the unlucky guy .. after reading all the answers.

We deploy on Friday's that too after office hours . :'(

The deployment process is quite lengthy and requires number of approvals and communication between 3-4 teams.

There are many instances when the deployment failed and emergency deployment lasted till 1-2 AM.

We deploy everytime except Friday evenings! Not just because of the bugs. Things like monitoring the performance and understanding/explaining the problems.

We don't deploy in the following time:

1. Friday Afternoon. No one present to fix emergency bugs.
2. At the end of the working day. Not as bad as Friday evening, but generally team will not be present for at least 12 hours in case something goes wrong.
3. Monday Morning! Too less time time to prepare deployment properly.

"Deployments should be treated as part of a development workflow, not as an afterthought." — source

We deploy major releases to production at a scheduled time, when the whole team is aware of. We just don't do it during the weekends because the traffic is very high and team members are unavailable. :)

We follow the same Dicky Martin's team process. We deploy in the morning too!

We code, review and keep the deployment ready for the next day before leaving. :)

We deploy code everyday in the morning. This gives us sufficient time to test the deployed code and push fixes when we are working at office.

That being said, there's no fixed time for deploying critical bug fixes. We deploy it as soon as possible.

Deploying on Friday evening: Oh man! Please don't unless you want to ruin your evening. ;)