My anime list is fairly accurate. However, I use it more so as a method of keeping track of what I want to watch/have watched /where I'm up to in anime rather than for counting how many days I've spent on it (though it is a nice bonus).
As such I don't put in re-watches. I don't feel the need.
My manga list in much less accurate. I don't put nearly as much time and effort into maintaining it. I don't update it often and therefore it isn't nearly as reliable as my anime list.