When I was unmedicated I would cycle quite rapidly. Insomnia is my biggest trigger. After a sleepless night I often got hypomanic.

Now when I'm on meds I can get mild hypomania if I sleep less than 4 hours, but it goes away if I get sleep the next night. Last November I got hypomanic because I was stressed and slept 3-6 hours a night for a week. it felt so amazing, I was so excited for everything and euphoric at times but also had some anxiety too. I wasn't taking my meds too regularly, and after a few days I stopped sleeping at all and the euphoria started turning into dysphoria. That was when I knocked myself out with meds and got some sleep and more stable.

So usually it happens overnight or during few days. When I was not on meds, the depression would also hit me during one day. The worst feeling ever, falling from the heights and hitting the rock bottom.