DateTime update? timer?

Hello, I’ve just noticed that the date times are not updated when the function is called.
I would like to use it to know precisely the time between 2 timer executions, even if the definition is a millisecond.
I would like to know how the timer really behaves, if the time between 2 executions is the time of the loop or if it is interpolated in the tick.
And I would like to know if a time value with higher precision is planned in the next version.

Thank you