I was looking for something not particularly regional, seasonal, mono-cultural, etc. for September. And guess what: I found that UNESCO (in 1966) named the 8th of September International Literacy Day. So the theme of the month is "literacy," and we're talking all things reading and readable. Some possibilities are books, libraries and bookstores, people reading . . .

Rules (just copy-pasted):

• Photos must be taken during this month and posted before voting starts.
• Photos must be taken by the posting member.
• Photos must be taken with your phone's camera.
• Post processing is allowed but you have to say what you did.
• Users must name the phone and software they used.
• Users post only one photo per entry.
• Users can change the entry only once.
• 3 day voting period starts on September 27th at 20:00 UTC and ends on the evening of September 30th.
• Winner of the vote should choose the next month competition theme.
• You are allowed to continue off topic on this thread after competition.

ed: because you can't just copy/paste a date and expect it to update.