Hi, You could add additional String attribute. And on save of object, you could call Java action to get the System.nanoTime(), set it on the attribute and save the object.
Mendix does not support nanoseconds out of the box yet.
All the dates are stored in the database with three digits after the seconds. So only milliseconds are supported. Nanoseconds not. You could of course use a string to store it that way but it depends a bit what you want to do with it.
Regards,
Ronald