I experience this, it used to be much worse 20 years ago when I could do more, went out more etc., I could lose days, literally, step outside a building in the morning and on the next step it was dark, with no other subjective indication anything was amiss. I'm pretty sure I wasn't just standing there midstep all day and in some cases there is evidence I was present at places I should be, acting as normal as I get (which isn't very), but I have no memory of it at all. It was put down to absence seizures at the time, but at the time they thought part of my problems was temporal lobe epilepsy, which has since been ruled out. More recently I am told by people I know that I still have these events but I am largely unaware of them.
I am surprised that this is not accepted as being part of the grab bag of goodies known as M.E. as I've pretty much accepted that it was.