JSFiddle - React, Tailwind, and code Playground

JavaScript

(function() {

  function curTime(pm) {
    var dt = new Date();
    var hr = dt.getHours(), min = dt.getMinutes(), sec = dt.getSeconds();
    var time = (pm ? ((hr+11)%12+1) : (hr<10?'0':'')+hr)+":"+(min<10?'0':'')+min+":"+(sec<10?'0':'')+sec+(pm ? (hr>12 ? " PM" : " AM") : ""); 
    return time;
  }
  
  alert("12-hour Format:    "+curTime(true)+"\n24-hour Format:    "+curTime(false));
  

})();