On a bright, sunny day so you can assess the light blocking quality of the installation from the inside as the work is being done. This is an electronics forum. The home improvement seminar is in the other banquet room down the hall to the left.
You might however get a better deal out of season, or simply want to get the job done soon. In that case (depending on your region) I would recommend waiting until about the second Tuesday in January, so to be sure that the company involved will be fully back to strength after the holidays.
In my experience, Mondays are not such a good idea. There is always a danger that the people doing the job will include some young fool still suffering from the effects of Saturday night. On the other hand, it's better not to wait too late: that increases the danger that some snag will take the job into a second week.
@ Lotus28: Seriously though, the English expression "homework" usually refers to assignments of work set for a pupil or student to do at home, or at least outside of school hours. It does not usually refer to home maintenance !