Date Range Timer

This revolves around a javascript function: checkDate(date1,date2)
It calculates and compares dates based on Mountain Standard Time, allowing for daylight savings.

jQuery

There is a jQuery call on every page to automatically handle elements with "data-start" or "data-end" defined:

Assign an element the attribute(s) of "data-start" or "data-end"; The element will be hidden initially and will not appear unless it matches the date criteria.
You can apply these attributes within the element's tag to create a start date, and end date, or both (a range).
Dates must be provided in this form: "August 2, 2013 13:30:00". The timezone is MST (-7/-6 offset).

<div data-start="October 13, 1975 11:13:00"
     data-end="August 2, 2013 09:13:00"></div>    

<div data-start="August 2, 2013 07:50:00"></div>

<div data-end="August 2, 2013 08:28:00"></div>

Custom

You can manually call checkDate() in your own functions and elements:

checkDate(startdate,enddate) returns true if the current MST time:
- Falls after startdate
- Falls before enddate
- Falls between startdate and enddate (if both are specified)
checkDate(startdate,enddate) returns false otherwise

 <div id="custom">
     Color Me
</div> 
 <script>
  
   var elem = document.getElementById('custom');
   var startdate = 'October 1, 1985 23:59:00';
   var enddate = 'October 1, 2015 00:00:00';
 
   if (checkDate(startdate,enddate)==true) {
      // falls within date range
      elem.style.border='1px solid red';
   }    
 
   if (checkDate(startdate,'')==true) {
      // falls after startdate      
      elem.style.color='green';
   }    
 
   if (checkDate('',enddate)==true) {
      // falls before enddate      
      elem.style.backgroundColor='#eeeeee';
   }  
</script>

Color Me