[SalesForce] how to view calendar in visual force page

You can use jQuery datepicker to show the calendar in a vf page. Please find the below example on how to implement jQuery datepicker and pass the value from VF page to controller. Hope this helps.

Update : To display more than one month numberOfMonths: parameters needs to be used.

VF Page

<apex:page id="myPage" docType="html-5.0" controller="JqueryDatePicker">

    <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css"></link>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.min.js"></script>
  <apex:form id="myForm">
      From Date: <apex:input type="date" id="fromDate" value="{!fromDate}" style="display:none;" /> <input type="text" id="fromDatePicker"></input>
      To Date: <apex:input type="date" id="toDate" value="{!toDate}" style="display:none;" /> <input type="text" id="toDatePicker"></input>
      <apex:commandButton value="Show Dates" action="{!showDates}" rerender="myPage"/>
      <script type="text/javascript">
          var $j = jQuery.noConflict();
              $j( "#fromDatePicker" ).datepicker({
                      numberOfMonths:2,
                      altField: "#myPage\\:myForm\\:fromDate",
                      altFormat: "yy-mm-dd"
               });
              $j( "#toDatePicker" ).datepicker({
                      numberOfMonths:2,
                      altField: "#myPage\\:myForm\\:toDate",
                      altFormat: "yy-mm-dd"
               });
               $j("#fromDatePicker").value($j("#myPage\\:myForm\\:fromDate").value());
               $j("#toDatePicker").value($j("#myPage\\:myForm\\:toDate").value());
      </script>
    </apex:form>
</apex:page>

Controller

public with sharing class JqueryDatePicker {
    public Date fromDate {get;set;}
    public Date toDate {get;set;}
    public JqueryDatePicker() {

    }
    public PageReference showDates() {
        System.debug('######### fromDate'+fromDate);
        System.debug('######### toDate'+toDate);
        return null;
    }

}

Screen-1

Screen-2