UPDATED: Not sure what happened when I tried to post before, but here's what I was trying to say:
It may be hard for people to believe, but even the city that doesn't sleep occasionally takes a break from drinking. A longstanding NY State law prohibits bars from selling alcohol from 4:00 to 10:00 AM on Sundays (and from 4:00 to 8:00 AM on weekdays). The state liquor authority grants all-night permits on an exceptional basis–but never, as the song says, on Sunday.
This year, New Year's falls on a Sunday, and Eris Evolution, a bar in Brooklyn, wishes to serve alcohol all night. The state liquor authority has declined to give the bar a permit, and Eris Evolution has sued in federal court, arguing that the NY restriction violates the Establishment Clause.