Currently posts can be edited for about 6 hours after a post is made. If you need an assist after that time has elapsed just message a moderator and we can help. There are several reasons for the limit and they include:
1. the possibility that a purloined account might be logged into and content altered or destroyed.
2. it's often better to respond to a thread with an update rather than to edit an existing post because folks don't go back and read content they've already read and so the update will be overlooked.