I've recently started to follow Tennis matches and championships more closely. Now I often hear schedules mention that a match will occurr not before a given time of day. That sounds odd to me. Below is an example:
Novak Djokovich vs. Roger Federer - 6PM
Rafael Nadal vs. Gustavo Kuirten - not before 8PM
I understand that by not before 8pm, the organizers mean that the match will start at 8PM sharp, or after that, if the previous match taking place on the same court takes longer than expected.
In this context, would it be semantically equivalent to use the expression "after" instead of "not before"?
In that case we would have:
Novak Djokovich vs. Roger Federer - 6PM
Rafael Nadal vs. Gustavo Kuirten - after 8PM
Wouldn't it be more direct and preferrable to just use the word after? The only difference I see between the expressions is that the word after excludes 8PM sharp, but to me that wouldn't be enough a difference to warrant the use of a more complex expression just for Tennis matches.
Finally, a question that may not be for this community, but rather for the Tennis enthusiasts: why don't they just simplify things and say "after 8PM"?