If you post it tonight it will count for October. Remember you can post your pic anytime during the month for it to count. If anyone has a tendency to forgot, just post very early in the month to get it over with.
Having people post monthly keeps the contest active and encourages more conversations, which in turn makes it fun IMO. It also keeps the contest pretty honest. We don’t want anyone to not post for months and then pop up with a giant piece saying it’s their frag when we haven’t seen it in forever.