Windows 11/10 includes tzutil.exe, a Command-Line Utility. This Windows Time Zone Utility can be used to change Time Zone or to get the current Time Zone details.

I'm looking for a simple desktop app that will run in the background and change the system time zone based on what wireless network I connect to. I consistently travel between CST and EST and both ...

You can change the Time Zone and Language settings as per your preference in Microsoft Outlook or Outlook.com on your Windows computer.