Time in North Dakota

A majority of North Dakota counties are located in the Central Time Zone, with 8 counties in the southwest, west of the Missouri River, following Mountain Time.
The counties which observe MST are as follows:

IANA time zone database

In the IANA time zone database, North Dakota is covered by five time zones to reflect changes in the border between the Central and Mountain time zones since 1970. Each of the five areas has had the same time within since January 1, 1970.
On October 25, 1992 Oliver County moved from Mountain Time to Central Time. The IANA time zone database entry is named for the county seat and largest city Center.
On October 26, 2003 all of Morton County moved to Central Time. Prior to this, the western part of the county had used Mountain Time. The database entry is named for New Salem, as the county seat Mandan was already using Central Time.
On November 7, 2010 Mercer County was moved from Mountain Time to Central Time. The database entry is named for the county's largest city, Beulah.
Columns marked "*" contain the data from the file zone.tab: