JS Countdown在IE和Safari中不起作用

Question

I have a javascript countdown which doesn't seem to be working on IE nor on safari, all tested on windows 7, works fine with chrome and firefox. I'm not looking to change to a jQuery countdown due to certain restrictions on the website so really looking to get this working across all browsers.

    <script language="JavaScript">
TargetDate = "January/01/2014 12:00 am";
BackColor = "";
ForeColor = "#000";
CountActive = true;
CountStepper = -1;
LeadingZero = true;
DisplayFormat = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds.";
FinishMessage = "<span class='finish'>Finished!</span>";
</script>
<script language="javascript">
function calcage(secs, num1, num2) {
  s = ((Math.floor(secs/num1))%num2).toString();
  if (LeadingZero && s.length < 2)
    s = "0" + s;
  return "<span class='digit'>" + s + "</span>";
}

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=' font-weight:bold; background-color:" + backcolor + 
                "; color:" + forecolor + "'> </span>");
}

if (typeof(BackColor)=="undefined")
  BackColor = "white";
if (typeof(ForeColor)=="undefined")
  ForeColor= "black";
if (typeof(TargetDate)=="undefined")
  TargetDate = "12/31/2020 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);
</script>

Countdown just displays as NaN. Any help greatly appreciated.

Answer 1

The following line is returning NaN

var dthen = new Date(TargetDate);

Your best bet, to ensure it'll work across browsers is to use the following Date constructor:

new Date(year, month, day, hours, minutes, seconds, milliseconds);

So, dthen will become:

var dthen = new Date(2014, 0, 1, 12, 0, 0, 0);

You may want to define those values at the top, like you have with TargetDate but this should put you on the right track.