Although grammatically incorrect, you asked is procrastinating bad or if the act of procrastination is bad, this is much like what I am achieving here, i am taking a break from my exam revision in order to come back fresher, and be able to concentrate more on the material that i am trying to remember.
Being overloaded with lots of information new or old can be daunting and stressful in some cases, with worrying whether you know all that you can know for the exam you are going to take, in my case very shortly within the week!
I am still in my first year at uni however so although i do care about my grades and i hope to achieve at least 70% overall for a first, the stress of it is not too much knowing that as long as I pass it does not count towards the final grade, but does help in securing a job placement for my 3rd year.
When is it bad to procrastinate? when you have a very close deadline, you shouldn’t rush. You also should take a bit more of a laid back approach to the work you are trying to produce!
Lots of Love