The name of "Anna Howard Shaw Day" is based on Liz's hatred of Valentine's Day, for which she substitutes "Anna Howard Shaw Day", a fictional holiday celebrating the real February 14 birthday of Woman's Civil Rights leader Anna Howard Shaw [REF].
The character Astronaut Mike Dexter was referenced in this episode, in which Liz tells the dental receptionist that she did not sign the liability waiver as her "boyfriend" Mike Dexter would come and take her home [REF].