Today I had an idea: I can write a plugin which provides those constants. Okay, not real time values, but at least the plugin can query on REAL Studio launch the current date and time and provide them as constants. As REAL Studio copies those constants into your application, they won't change. The plugin will also not update those constants as the plugin is not part of the application.
So next plugin prerelease will have a BuildConstantsMBS module with constants named time, date and datetime.
I thought about possibly other constants like the name of the user or the machine so you know who compiled the application. What do you think?