Actually the settings in the AdminCP are that you have
15 minutes from the original posting to review and edit your own post. That certainly seems a reasonable amount to actually read/review your own post and edit any errors or make additions.
All that means is that you should
ACTUALLY READ WHAT YOU POST AFTER YOU HIT THE SAVE BUTTON. IF YOU SEE A MISTAKE, OR FORGOT TO SAY SOMETHING AND WANT TO ADD TO WHAT YOU WROTE, THEN YOU CAN STILL EDIT/CHANGE IT FOR 15 MINUTES.
If you want to add additional information, or correct something you said
after that time, you can always post a new post with the correction or additional information!
If the consensus of the group is that more time is desirable, that time can be increased somewhat, but some limit is clearly reasonable because if posters can always go back and edit their posts, no one will know that they actually have been edited. During whatever timelimit is set, the post will contain a notetation which states: "Last Edited by" and identify who edited it, either the original poster's username, or the moderator or administrator who edited it.
Regards,