When Chloe and Gabe first visit the restaurant he has no beard. Later that evening, when Gabe calls Chloe to talk about their visit to the restaurant his beard appears to have been growing for at least a week.
The Memory Book has a ticket stub for Rick Nelson performing at the Greek Theater in Griffith Park on September 22, 1969. Engelbert Humperdinck was performing at the Greek Theater on September 22, 1969.