Here's an ActiveX Calendar Control example that you can use within an HTA. It demonstrates how to display a Calendar and return a selected date.
Simply copy the code into a text file and name it with an HTA extension.
Enjoy.
<HTML>
<HEAD>
<TITLE>Show Date Calendar</TITLE>
<HTA:APPLICATION
ID="HTACalendarControl"
APPLICATIONNAME="HTACalCtrl"
SCROLL="no"
SINGLEINSTANCE="no"
WINDOWSTATE="normal"
>
<SCRIPT type="text/VBScript">
Sub Window_Onload
self.ResizeTo 350,300 'w,h
self.MoveTo 1,1
End Sub
Sub ShowDate
DateVal = Calendar1.Value
MsgBox DateVal
End Sub
</SCRIPT>
</HEAD>
<body STYLE="filter:progid:DXImageTransform.Microsoft.Gradient
(GradientType=1, StartColorStr='#0000AA', EndColorStr='#000055')">
<p align="center">
<OBJECT CLASSID="clsid:8E27C92B-1264-101C-8A2F-040224009C02" id="Calendar1"></OBJECT></p>
<p align="center">
<input type="button" name="OKButton" value="Show Date" onclick="ShowDate">
</p>
</BODY>
</HTML>