Standard time in Kazakhstan is either UTC+05:00 or UTC+06:00. These times apply throughout the year as Kazakhstan does not observe Daylight saving time.
The IANA time zone database identifies five zones for Kazakhstan. Data in columns marked * are from the file zone.tab of the database.
According to an email on the tz mailing list, Kostanay Region could be part of Asia/Qyzylorda [1].
Notes: