Rescheduling Oath

I just had my interview at LIC office on Monday August 6, 2012 at 3:15 pm. Everything went great and the officer was really warm and friendly. Before I was called in I noticed that everyone who came out of the interview was being given an oath date of August 29th. When my interview was finished the officer said I would get an oath letter in the mail because it was after 3pm and they don't give letters after 3pm. I asked if it would be for August 29th, and she said she was not sure whether it would be that day or in September. Now, I had been told by plenty of friends that between their interview and oath the max time was 2 weeks, and me being optimistic me, I had alreaady made plans to travel during labor day to Canada. I have green card and asylee status and my travel document expired two months ago. Is there any chance that in case my oath letter arrives and has a date on it for September that I can go and ask if I can reschedule the oath for an EARLIER time? Has anyone had success with that?