they always work for me, but it depends on the subject.
if its like ict which only requires regurgitating answers from previous mark schemes, it works. (5pm - 12am~10am-12pm)
If its psychology when vasts amount of information needs to be understood and written, no chance.
I learned that revising and then sleeping on it, actually helps you (well it does for me) retain the information. You may not be able to say it out the next morning, but you'll be able to write it.