From the description of the UI of your endpoint, it sounds like a regular MX300, and not a G2.  The G2 has a solid blue background and a large clock, there isn't really a notable top status bar.  The earlier model MX300 has the status bar and clock in the top right corner.  In either case, it isn't possible to customize the UI in the way you're wanting, matter of fact the MX Series doesn't really have any customization at all regarding the UI with the exception of the encryption indicator.  I'm not able to get a picture of the two current types of UI until tomorrow.  You could submit a feature request through your Cisco Account Manager to see if they might add the date.  However, if the UI is the older version, I wouldn't expect such a feature to get an traction due to that line of endpoint software isn't getting any active development with the exception of maintenance to fix bugs etc.