In the current job I am on there are significant patches of time where I do not have a ticket and any tickets I could take will rely on other peoples in those cases I tend to read or watch instructional videos on technical subjects but as a general rule not directly related to my work since I am pretty competent at my job and the amount of benefit I can glean is minimal.

I would say often 4-8 hours a week.

Also some times if I have had a full day and done a lot but it is still early to take off and I don't want to start on anything I will read or watch videos. This will be the issue in any job really, so I would say at the minimal I do 1-3 hours a week on reading and instructional video watching.