Is it possible to edit a question I have posted?

If it’s been less than 10 minutes, there should be a link that says edit question. If it has been more than 10 minutes, that goes away. You would need to flag your question and in the comment section say that you would like to edit your question. Once a mod sees that, they will be able to return the question to you for editing.

Additional note: if you are editing and do not save within 10min, the original will stand. So it’s not 10min to hit the [Edit] button, it’s 10min to be done with your edit(s) and hit the [Save] button.

It is that way for sure with Answers. I believe it is the same with Questions.