At the beginning of the movie they talk about summer being almost over. The second day at the store, Charley stands by a wall calendar that says August, then when he gets home his sons give him a Father's Day card and he says "That's right, Sunday is Father's Day" which would mean it was mid-June.
During the chase scene, while Charley is speaking to the angel, the background shows a modern car in a driveway when the setting is supposed to be 1933.