When Dwight forces Gabe to take him to Robert California's house, Dwight yells out Robert California's name to see which unit he lives in. Robert California sees them and lets them know to come around to his unit: 102. Later on when Robert California invites them into his condo, the placard outside his condo says 1-121.
After Kelly correctly answers the trivia question about the Jewish holiday that celebrates the new year for trees, she then refers to "the month of Tu BiShvat." "Shevat" is the correct name for the month that the holiday falls in, as Tu BiShvat means "the fifteenth day of Shevat" in English and is only a single day long.