JSFiddle - React, Tailwind, and code Playground

by Amar Nyayapati

JavaScript

function calcage(secs, num1, num2) {
    s = ((Math.floor(secs/num1))%num2).toString();
    if (LeadingZero && s.length < 2)
        s = "0" + s;
    return "<b>" + s + "</b>";
}

function CountBack(secs) {
    if (secs < 0) {
        document.getElementById("cntdwn").innerHTML = FinishMessage;
        return;
    }
    DisplayStr = DisplayFormat.replace(/%%D%%/g, calcage(secs,86400,100000));
    DisplayStr = DisplayStr.replace(/%%H%%/g, calcage(secs,3600,24));
    DisplayStr = DisplayStr.replace(/%%M%%/g, calcage(secs,60,60));
    DisplayStr = DisplayStr.replace(/%%S%%/g, calcage(secs,1,60));

    document.getElementById("cntdwn").innerHTML = DisplayStr;
    if (CountActive)
    setTimeout("CountBack(" + (secs+CountStepper) + ")", SetTimeOutPeriod);
}

function putspan(backcolor, forecolor) {
    document.write("<span id='cntdwn' style='background-color:" + backcolor +
                   "; color:" + forecolor + "'></span>");
}
if (typeof(BackColor)=="undefined")
    BackColor = "white";
if (typeof(ForeColor)=="undefined")
    ForeColor= "black";
if (typeof(TargetDate)=="undefined")
    TargetDate = "11/01/2014 5:00 AM";
if (typeof(DisplayFormat)=="undefined")
    DisplayFormat = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds.";
if (typeof(CountActive)=="undefined")
    CountActive = true;
if (typeof(FinishMessage)=="undefined")
    FinishMessage = "";
if (typeof(CountStepper)!="number")
    CountStepper = -1;
if (typeof(LeadingZero)=="undefined")
    LeadingZero = true;
    CountStepper = Math.ceil(CountStepper);
if (CountStepper == 0)
    CountActive = false;
var SetTimeOutPeriod = (Math.abs(CountStepper)-1)*1000 + 990;
putspan(BackColor, ForeColor);
var dthen = new Date(TargetDate);
var dnow = new Date();
if(CountStepper>0)
    ddiff = new Date(dnow-dthen);
else
    ddiff = new Date(dthen-dnow);
    gsecs = Math.floor(ddiff.valueOf()/1000);
    CountBack(gsecs);