I have made minor edits to 2 posts after 24 hours, and they went through fine - without affecting the votes. But Steemit can change, because it is still in its early development. So I try to be open to whatever happens. It was nice of @steevc to transfer 6 cents to me -- Thanks, Steevc! -- in case it didn't work out. I do know that a post becomes permanent after 30 days. No comments or edits can be made at all after that.