If someone referred to "last August" in a conversation that took place in December 2015, would the speaker be referring to August 2014 or August 2015?

Example sentence: "I saw you last August".

Further, how would the date of the conversation affect the meaning of "last August"? 

That is, would the year referenced change if the conversation took place in 

1. September 2015?
2. January 2016?
3. July 2016?