The tz database says that Kazakhstan has three time zones.  I was asked by a correspondent to check that statement.  There is evidence that suggests that the two western zones have been consolidated, but it's not conclusive.  This is a summary of the evidence; perhaps someone else on the mailing list can find a definite answer.
 
I know that most time zone sites on the internet get their information simply by copying from someone else, so I tried to check sources that I know have independent information.
 
The web page of the Kazakh embassy in the U.K., http://www.kazakhstanembassy.org.uk/cgi-bin/index/55, says that there are two time zones, and that Astana is on UTC+6.  The page has no update date, but includes other information dated February, 2005.  The web page of the Kazakh embassy to Belgium at http://www.kazakhstanembassy.be/Kazakhstan.asp, on the other hand, shows three time zones (Eastern/Main, Central, and Western).  It has a copyright date 2004.
 
The December, 2004 Official Airline Guide (OAG) showed three time zones for Kazakhstan; the current online data from OAG show only two.  I believe the OAG gets its data from the IATA SSIM, which in turn gets its data from member airlines.
 
The time zone map in the CIA World Factbook online, dated "3-05", also shows only two zones.  However, I can also find CIA World Factbook time zone maps dated "7-03" and "4-01" that show the same two zones, suggesting that the CIA map has been consistently wrong.  The "6-99" map shows two time zones but with a different coverage:  Qyzylorda Oblysy is shown in UTC+5 instead of UTC+6.
 
Another small piece of evidence for two zones:  the Worldtimeserver website has a map (http://www.worldtimeserver.com/current_time_in_KZ.aspx) that apparently shows Kazakhstan divided into three time zones.  However, its list only gives two time zones for Kazakhstan (Eastern and Western), and the map for Western only shows two zones.  This suggests that the webmaster for that site recently altered the map for Western, but forgot to change the Eastern map to match.
 
It's tempting to think that the UTC+4 zone was switched to UTC+5 at the same time that DST was abolished in Kazakhstan, March 15, 2005.  The Kazakh embassy in the U.S. has a newsletter on its website with an article about the abolition of DST (http://www.kazakhembus.com/031705.html), but it doesn't mention time zones being consolidated.
 
If two zones is correct, Asia/Aqtau and Asia/Oral should be changed from UTC+4 to UTC+5 in the tz database.  The effective date for this change was probably quite recent.
 
-- Gwillim Law