Is suicide spontaneous?

Hopefully, my thread title makes sense. To those who actually complete suicide, is it a spontaneous action or something that is planned? For me, I think it would be very hard to set a time and day where I would actually go through with it. I know that I have bad days and I eventually come out of it. However, if I was having extremely emotional day and I had access to a <mod edit - method>, I could easily see myself making a spontaneous decision and pulling the the trigger. Is this how suicide happens or are the details more planned out?

Thanks!