When Does "The Catastrophic History of You and Me" (2012) Take Place?
"The Catastrophic History of You and Me" is a fantasy romance novel written by Jess Rothenberg that released January 1st, 2012. So when is "The Catastrophic History of You and Me" set?
It takes place in the year:
We know this because Aubrie "Brie" Elizabeth Eagan lists her "favorite movies" that play over and over in some form of afterlife and this includes "Across the Universe" (2007), a film that released in some theaters on September 14th, 2007 AD (and wide release on October 12th, 2007 AD). So it must be after September of 2007 AD.

2010 AD - 2011 AD
We know this because Aubrie "Brie" Elizabeth Eagan lists her "favorite movies" that play over and over in some form of afterlife and this includes "Across the Universe" (2007), a film that released in some theaters on September 14th, 2007 AD (and wide release on October 12th, 2007 AD). So it must be after September of 2007 AD.
More specifically, Aubrie narrates to the reader, ..."all of that changed on the night of October 4, 2010—". This is the inciting incident of the plot. So the narrative starts in October of 2010 AD.
Partway through Aubrie asks aloud, "What day is it? What month is it?" and she's told, "June. June twelfth." Her thoughts race: "June 12. June 12. JUNE 12." so we know the novel has continued deep into the next year, to June of 2011 AD.
Near the end of the story, after her mother says, "October fourth." Aubrie "grabbed the newspaper sitting on the counter" and says out-loud, "October 4, 2010. Last year." confirming that we are (or, at least, just previously were) in 2011 AD.
2010 + 1 = 2011.