“tzutil.exe” is a command line utility introduced in Windows Vista (also in Windows 7 and Windows 2008) which can be used to change Time Zone or to view the current time zone information. To use this command (from a command prompt as administrator):

tzutil /g – To view current time zone
tzutil /l – To get a list of all available time zones
tzutil /s <time_zone_ID> – To change time zone

time_zone_ID is the new time zone which you want to set. For example, if you want to set the time zone to Eastern, Central, Mountain or Pacific Daylight Time, you would use any of the following:

tzutil /s "Eastern Daylight Time"
tzutil /s "Central Daylight Time"
tzutil /s "Mountain Daylight Time"
tzutil /s "Pacific Daylight Time"

Windows change timezone command.