MeaKitty Cheers for the question.
Good to know you found the edit button. I'd say you've passed the edit expiry period where you're allowed to edit the post.
It's becoming more widely adopted across a number of community software like this one (Flarum is the software btw, if you want to check it out).
From memory, the idea behind limited time editing windows is so that the original poster can't change the content after people have forgotten about it.
ie. Bob posts a wholesome post. Everyone likes it. One year later, Bob edits wholesome post into a swastika and everyone who's liked it is now tagged as liking that post (post revisions would be useful to combat these but nobody reads them).
