JSFiddle - React, Tailwind, and code Playground

HTML

<script>
var dates = [{ "name" : "PHISH Reba Comcast Center Hartford CT. 6/18/2010" },{ "name" : "Phish - Destiny Unbound 1991 Telluride" },{ "name" : "Phish 1991-11-30 Harry Hood" },{ "name" : "Phish - Harry Hood - November 30, 1991" },{ "name" : "Phish - It's Ice - November 30, 1991" },{ "name" : "PHISH - 11.30.91 BOUNCING AROUND THE ROOM" },{ "name" : "PHISH - 11.30.91 Harry Hood" },{ "name" : "PHISH - 11.30.91 It's ICE" },{ "name" : "Phish - My Sweet One/Horn - November 30, 1991" },{ "name" : "PHISH - 11.30.91 HORN" },{ "name" : "Phish - My Sweet One/Horn - November 30, 1991" },{ "name" : "PHISH - 11.30.91 I didn't know" },{ "name" : "Phish/Worcester,MA 12-31-91 \"Llama\" (photo montage)" },{ "name" : "Phish 1991-11-30 My Sweet One, Port Chester, NY" },{ "name" : "Cavern - Phish" },{ "name" : "Phish -- Suzy Greenberg 2/25/93" },{ "name" : "Phish - David Bowie 2/25/93" },{ "name" : "PHISH - 02 - Fast Enough For You" },{ "name" : "Phish 1993-2-25 If I Only Had a Brain w/ Mimi on Vac" },{ "name" : "Phish-Good Times Bad Times, 1993/2/25" },{ "name" : "Phish Foam Madison Square Garden 01/01/2011 [HD iPhone]" },{ "name" : "Phish: Foam [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish | 01.01.11 | Foam" },{ "name" : "Phish: Tube / Runaway Jim [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish \"Runaway Jim\" @ MSG on January 1, 2011" },{ "name" : "Phish | 01.01.11 | Runaway Jim" },{ "name" : "Phish My Soul Madison Square Garden 01/01/11 [HD]" },{ "name" : "Phish | 01.01.11 | My Soul" },{ "name" : "Phish: My Soul [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish | 01.01.11 | Tube" },{ "name" : "Phish: Tube / Runaway Jim [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish: Guelah Papyrus [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish | 01.01.11 | Guelah Papyrus" },{ "name" : "Phish Reba Madison Square Garden 01/01/11 [HD]" },{ "name" : "Phish: Reba [HD] 2011-01-01 - New York, NY" },{ "name" : "Phish | 01.01.11 | Reba" },{ "name" : "Phish \"Reba, pt.1\"...

JavaScript

var extractDateFromString = function(str) {
    var m = str.replace((new RegExp(' ', 'g')), '').match(/(([0-9]{1,4}).?([0-9]{1,2}).?([0-9]{1,4}))/)
    if (m === null) console.log("fail (" + str + ")\n")
    else console.log("pass " + m + " (" + str + ")\n")
}
for (var i = 0; i < dates.length; i++) {
    extractDateFromString(dates[i].name)
}