JSFiddle - React, Tailwind, and code Playground

by fenve

HTML

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<input type="text" id="starttime" value="10:00 PM" />
<input type="button" id="btnConvert" value="Convert to 24 Hours" />

JavaScript

function ConvertTimeformat(format, str) {
    var time = $("#starttime").val();
    var hours = Number(time.match(/^(\d+)/)[1]);
    var minutes = Number(time.match(/:(\d+)/)[1]);
    var AMPM = time.match(/\s(.*)$/)[1];
    if (AMPM == "PM" && hours < 12) hours = hours + 12;
    if (AMPM == "AM" && hours == 12) hours = hours - 12;
    var sHours = hours.toString();
    var sMinutes = minutes.toString();
    if (hours < 10) sHours = "0" + sHours;
    if (minutes < 10) sMinutes = "0" + sMinutes;
    alert(sHours + ":" + sMinutes);
}

$("#btnConvert").on("click", function () {
    ConvertTimeformat("24", $("#txttime").val());
});