As far as I am aware it is only the Super League, which should have started this weekend, that has been postponed until 5 September. I doubt if the main league will start until later in September. Which league is ΟΦΗ in?
The official ΟΦΗ web site
isn't showing any fixtures at the moment. The page showing games
seems to be showing the results of last years fixtures at the moment. Whether it will start showing fixtures nearer the time I have no idea. Some of my friends support a small local team. They usually ask in the café about midweek when and where the weekend's match will be and typically nobody knows. The people they are asking are players on the team. If the first match is 5 September I would expect the fixture to be publicised on 4 September, or possibly 6 September.
If you are searching for information in Greece try using www.google.gr
and, if possible, write the search term in Greek.