This movie takes place in the summer, as is made clear by some conversation between Woody and Mike early in the film. When Woody, 'Herbert' and Delilah drive downtown, some shots reveal a good amount of Christmas decor (neon Santa Clauses all down the street can be seen in one of the scene's first shots). Also during the downtown drive, a theater marquee lists December dates. On top of this, some scenes that take place on residential streets show trees well into Autumnal states.
When "Herbert" takes Delilah over to his apartment, a crew member's suited pant leg and dress shoe can be seen in the corner of the shot.