The Bangles, Prince and the Use of the Subjunctive

(Don't call it a comeback, we been here for years ... wait, that's LL, but still stands as a nice segue from our prolonged absence. Onward.)

I was going about my customary Sunday shopping at Albertson's yesterday when a line from the Bangles' "Manic Monday" caught my ear: "I wish it were Sunday."

Fantastic! I thought. These chicks (turns out it was Prince) know the difference between the subjunctive and the indicative! Susanna Hoffs realizes it isn't actually Sunday, she just wishes it were Sunday! They get it. Pop culture acknowledges the English language.

Why is it, then, that every lyrics site I find has the line as "I wish it was Sunday"? Did I hear the line incorrectly? Am I such a word nerd that I internally edit what I hear so that improper usage won't cause me continual mental meltdown? Or did these lyrics folks just transcribe the song in error?

Is there a 1980s music aficionado in the house? Help me.