One thing, that I can do for hours without realizing the time is passing is watching shows. Sometimes, when I start watching a new show, I get hooked and I just want to keep watching. I will just keep watching more episodes and then I realize I have been watching for hours. This usually happens with shows that are interesting and new. It is not good to watch too much, but within reason is okay. For me, finding a new and thrilling show is an easy way to pass the time.