JSFiddle - React, Tailwind, and code Playground
JavaScript
//12-hour to 24-hour
alert((new Date()).toLocaleString().replace(/(.+ )(\d+)(:.+)(\wM)/g, function replacer(match, p1, p2, p3, p4) {
return p1 + (p4 === "PM" ? (12 + Number(p2)) : p2) + p3;
}));