On Stack Exchange sites, edits that are made within 5 minutes of posting a question or answer aren't counted. This is called the grace period.

For example, if you post a new answer, and edit it after the 5-minute grace period, then this is how it'll look like:

If you make the edit within the grace period, then it'll look like:

It'd be great if you can see a countdown timer that starts counting down immediately after you post a question or answer. Might be pointless, but what do you think?