How can I calculate the duration of a metric that does not have and end date by using todays date?

[Ronald Harper]

I would like calculate the duration of the rejected value using today's date/

[Uncle Rob]

Ok, metric definitions and instances are tricky.  
The metric definition is saying "log the amount of time <this field> had its current value".
Every time the value changes, the "old" metric instance gets its end date and calculation set to complete.
But that makes "final" states kinda wonky.  Because that last state value will never change... its metric instance just stays open like that.

So my question would be... what do you want the start->end of the rejected value to represent?

[Ronald Harper]

Hi Robert, rejected was just an example.  The demand states I'm more interested in are  (Draft, Screening, Submitted, Qualified, Deferred, and Approved).

Management want to know a true picture of how long a demand has been sitting in the mention states.

Thanks

[Uncle Rob]

Metric Instances on State should do *exactly* that, with the exception of the end-states I mentioned earlier.

So if we remove rejected from the equation, what's still missing?