Jack tells Maya that he was present for her birth, and that it was the hottest day of the year. According to season 1, Maya's birthday is January 1.
Maya claims her birthday is 5 months away, but if we assume events are taking place fairly close to the real air date (which was true for the recent Christmas episode) of January 17th, this is very wrong. Season one clearly establishes that Maya's birthday is January 1st meaning it's either 2 weeks past or 11 1/2 months away but it would be very reasonable to say January 1st occurs during the current events.