I vary. When I'm not messing with med changes, I have a stable pattern of about 4 days hypomanic and irritable, swinging slowly down over a week to a low of mild depression, then back up more rapidly to hypomania again. But things like med changes (e.g. introduce a neuroleptic) and I get very erratic and intense shifts within a day. It hardly fits DSM-IV's idea of Bipolar criteria, but it has landed me in hospital a couple of times.