The sudden inability of
your friends to commit to attending your event or party out of fear that something better may come up that they wish to attend. This
affliction presents most often around the
New Years Eve holiday, where it gets its name, given the large number of competing parties to choose from.
"Are Bob and Susan coming tonight?"
"
I don't know, they kept saying they weren't sure if they could make it."
"Sounds like
New Year's Eve Syndrome; Mike decided today to
throw a party tonight; they probably went there instead; a-holes."