Adjust Time and Date Format (Compliant with ISO 8601)

  • Display the configuration editor in the system menu by following these steps:
    Click on System → Preferences → Main Menu
    Enable: Applications → System Tools → Configuration Editor (gconf-editor)
  • Now open the Configuration Editor (gconf-editor) and do the following:
    • Navigate to / → apps → panel → applets → clock_screen0 → prefs
      and set the value of custom_format to %Y-%m-%d %H:%M:%S. (note: this is the php strftime() format.)
    • Under "format" in the same location change 24-hour to custom