It can take anywhere from 1-15 min. Depending on your priorities. One can be as brief or thorough as one chooses. I like to incorporate something I want to do for myself.
Usually just a few minutes. The things I put on the list first are usually the things I want/need to do first. Then over the course of the day I add to the list if needed.
Not even 5 minutes. Especially if you do it everyday. And I go on from the previous day. And, if I know I have to do something tomorrow, I write it in today.