To set the Time Zone from the command line, use:
RunDLL32 shell32.dll,Control_RunDLL %SystemRoot%\system32\TIMEDATE.cpl,,/Z <Display or Std Value>
where <Display or Std Value> is the data value of the Display Value Name, or the Std Value Name
,at
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\Current Version\Time Zones\<The Zone Key>.
You can also use:
Control.exe %SystemRoot%\system32\TIMEDATE.CPL,,/Z <Display or Std Value>.
Example:
RunDLL32 shell32.dll,Control_RunDLL %SystemRoot%\system32\TIMEDATE.cpl,,/Z US Eastern Standard Time
NOTE: You do NOT encapsulate the time zone string in quote (") marks.