Seperation Date

My Spouse left a house in August of 08 as well as he is revelation me which this is a date of seperation even yet he didn't file for divorce until May of 09.  He didn't do this deliberately which we can tell, though it is an area of contention now as well as do we have any real grounds for fighting this in court.  My assumption is which you went to 2 or 3 matrimony couseling session in a fall of 09 so we would reason which a clock upon a 2 year period in PA would start in Dec of 08 as well as not August of 08