[Paul Stenning]

See the attached screenshot from the admin system which shows the time limits here.

As Paul said, it is to prevent threads becoming nonsensical. For example by changing information after people have responded to the original version or, worse, by mellowing an argumentative post to make it appear as if the respondent started the argument.

If you require an edit after the limit just click the red triangle to report the post to request it or PM a moderator. As long as the edit doesn't affect the flow of the thread we will do it.

Of course information that was not apparent at the time of the post but was discovered by further investigation etc would belong in a follow-up post anyway.