I'm on the fence about woo things, however I do like reading stories.
There are lots of stories about time slip experiences, with the most well known being Bold Street, Liverpool. The stories I find interesting are when more than one person (from the 'present' time) sees the 'past' at the same time. In that case it can't be a hallucination - they're either both colluding liars or they really did see 'something'.
Has anyone had any such experiences? I suppose if such a thing exists, we could 'slip' an hour or a day into the past and not even realise.