What's your accent?

[angus]

I got pretty much the exact opposite of you (heavy on New York/New Jersey and Louisiana, but light on the Pacific Northwest):



I think maybe we got different questions, though.  I didn't see anything about a dance or about potatoes, or about spendy or coffee slang.  Mine asked me about things like the night before Halloween (I have no special name for this); the grassy area just outside the sidewalk, which I just call the grassy area outside the sidewalk; and a drive-through liquor store, which I just call a drive-through liquor store.  

My cities were New York, New Orleans, and Yonkers.  

[angus]

Looks like I have a NC accent:

Wow, you're like Andy Griffith.  But without the uniform.  And the fatherly advice.  And maybe with a few more captives in your basement.

Looks like you have some Long Island speak as well.  I got that too, even though I don't actually pronounce Long Island as one word.

[angus]

So drive through liquor stores? Wtf?

I just call them drive through liquor stores.  I've not seen any in Pennsylvania--in fact, the state has a weird monopoly on all liquor sales in Pennsylvania--but I've been to a few elsewhere.  New Hampshire comes to mind.  There they look like big barns and you drive up and stop at a window and tell them what you want and they hand it to you.

When I was much younger the drive-through bars were common enough as well.  You drive up and say, "I want a margarita, rocks, no salt" and in a minute or so they'd hand it to you in a big plastic to-go cup so you could drive around with a cold, refreshing beverage.  Then states started passing open-container laws.  I haven't seen any of those since I was about 20 years old, but I remember being in high school and getting mixed drinks with my buddies and driving around drinking them.  Misspent youth.  The minimum age to buy liquor then was 18 but it wasn't much enforced back then.  Only occasionally would someone ask me for an ID.  Then the drinking age started increasing, state by state, and now they're all 21.  I think the last holdout was Louisiana.  They stayed at 18 till I was about 27 or so.  Not only did the drinking age increase, but enforcement actually increased as well. 

The drive-through liquor stores still exists though, and so long as they don't sell open containers or to any one under the age of 21, they'll probably continue to exist.  (Except in Pennsylvania.)

[angus]

(do you need a sort for a day that's already before another one?)

Yes, it's called "other one eve."  For example, All Hallows Eve (Halloween) proceeds All Hallows Day.  The relevant question is, do you need a word for the day that's before the day before another one?  Hallows Eve's Eve?  Christmas Eve's Eve?  

I had no idea that anyone had a special word for October 30, other than October 30, so I looked up.  Apparently there's no universal standard, but many terms exist.  A cursory internet search turned up Mischief Night, Goosey Night, Hell Night, Cabbage Night, Gate Night, Devil's Night, Devil's Eye, Trick Night, and Mat Night, among others.

I do think you're probably right in your analysis of Michigan.  Take a look at this map from a Harvard linguistics department study:



Although it would not explain my affinity for Michiganspeak over other parts of the upper midwest.  I've only spent the night in the state once.  I wasn't there long enough to pick up on Devil's Night.