Mongolia 2005

Several sources say Mongolia has only 2 time zones with DST. The TZ asia file says 3 time zones. http://www.travelmongolia.org/travel.mongolia/travel.info.html reads: " Time Difference Mongolia is 8 hours ahead of GMT in winter and 9 hours ahead in summer. The three western aimags of Mongolia, Uvs, Bayan Ulgii and Khovd are one hour behind Ulaanbaatar and the rest of Mongolia. " MIAT Mongolian Airlines (http://www.miat.com/frame.php?page=travel_information ) also speak of 2 time zones, as does the usually well informed worldtimeserver.com Does anybody have more evidence on the real situation? Oscar van Vlijmen 2005-05-16