Arizona Time

Your system seems to allow only for Mountain Standard Time (MST) in the US--it does not differentiate between the period when times convert to Daylight Savings Time (Mountain Daylight Time (MDT)).  This is a problem for those of us who living in Arizona, where we do NOT convert to Daylight Savings Time.  In other words, Arizona is on MST all year (sometimes called Arizona Time) while the rest of the time zone in the US converts to MDT.  With the time change coming up soon, can you implement a fix urgently?  

Thanks