This day is on February 14, which is the day that it dawns on you that you are alone.
Often when everyone else has a valentine.
(also the acronym for it is SAD)
Kelly: So me and Jim are going to the movies on Valentine's day, what are you doing?
Sally: Well I'll do what I do every year on single-awareness day; i'll watch chick flicks
and eat until I become even less attractive.
Kelly: Wow thanks for killing my mood.
Sally: No prob.