function formatraw(date, format, utc) {
let raw = new Date(date.split(" ").join("T"));
let res = format.slice();
const MMMM = ["\x00", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
const MMM = ["\x01", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
const dddd = ["\x02", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
const ddd = ["\x03", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
function ii(i, len) {
let s = i + "";
len = len || 2;
while (s.length < len) s = "0" + s;
return s;
}
const y = utc ? raw.getUTCFullYear() : raw.getFullYear();
res = res.replace(/(^|[^\\])yyyy+/g, "$1" + y);
res = res.replace(/(^|[^\\])yy/g, "$1" + y.toString().substr(2, 2));
res = res.replace(/(^|[^\\])y/g, "$1" + y);
const M = (utc ? raw.getUTCMonth() : raw.getMonth()) + 1;
res = res.replace(/(^|[^\\])MMMM+/g, "$1" + MMMM[0]);
res = res.replace(/(^|[^\\])MMM/g, "$1" + MMM[0]);
res = res.replace(/(^|[^\\])MM/g, "$1" + ii(M));
res = res.replace(/(^|[^\\])M/g, "$1" + M);
const d = utc ? raw.getUTCraw() : raw.getDate();
res = res.replace(/(^|[^\\])dddd+/g, "$1" + dddd[0]);
res = res.replace(/(^|[^\\])ddd/g, "$1" + ddd[0]);
res = res.replace(/(^|[^\\])dd/g, "$1" + ii(d));
res = res.replace(/(^|[^\\])d/g, "$1" + d);
const H = utc ? raw.getUTCHours() : raw.getHours();
res = res.replace(/(^|[^\\])HH+/g, "$1" + ii(H));
res = res.replace(/(^|[^\\])H/g, "$1" + H);
const h = H > 12 ? H - 12 : H == 0 ? 12 : H;
res = res.replace(/(^|[^\\])hh+/g, "$1" + ii(h));
res = res.replace(/(^|[^\\])h/g, "$1" + h);
const m = utc ? raw.getUTCMinutes() : raw.getMinutes();
res = res.replace(/(^|[^\\])mm+/g, "$1" + ii(m));
res = res.replace(/(^|[^\\])m/g, "$1" + m);
const s = utc ? raw.getUTCSeconds() : raw.getSeconds();
res = res.replace(/(^|[^\\])ss+/g, "$1" + ii(s));
res = res.replace(/(^|[^\\])s/g, "$1" + s);
let f = utc ? raw.getUTCMilliseconds() : raw.getMilliseconds();
res = res.replace(/(^|[^\\])fff+/g, "$1" + ii(f, 3));
f = Math.round(f / 10);
res = res.replace(/(^|[^\\])ff/g, "$1" + ii(f));
f = Math.round(f / 10);
res = res.replace(/(^|[^\\])f/g, "$1" + f);
const T = H < 12 ? "AM" : "PM";
res = res.replace(/(^|[^\\]){TT}/g, "$1" + T);
res = res.replace(/(^|[^\\]){T}/g, "$1" + T.charAt(0));
const t = T.toLowerCase();
res = res.replace(/(^|[^\\]){tt}/g, "$1" + t);
res = res.replace(/(^|[^\\]){t}/g, "$1" + t.charAt(0));
let tz = -raw.getTimezoneOffset();
let K = utc || !tz ? "Z" : tz > 0 ? "+" : "-";
if (!utc) {
tz = Math.abs(tz);
let tzHrs = Math.floor(tz / 60);
let tzMin = tz % 60;
K += ii(tzHrs) + ":" + ii(tzMin);
}
res = res.replace(/(^|[^\\])K/g, "$1" + K);
const day = (utc ? raw.getUTCDay() : raw.getDay()) + 1;
res = res.replace(new RegExp(dddd[0], "g"), dddd[day]);
res = res.replace(new RegExp(ddd[0], "g"), ddd[day]);
res = res.replace(new RegExp(MMMM[0], "g"), MMMM[M]);
res = res.replace(new RegExp(MMM[0], "g"), MMM[M]);
res = res.replace(/\\(.)/g, "$1");
return res;
}
console.log(formatraw("2019-01-06T23:29:35.000Z","MMMM dd, yyyy"))