Getting the diff between two values has me puzzled

I am trying to get the amount of time an object takes between certain stages.

But I’m having issues so decided to get more simple and just see if I can get the difference between two values. Warning - I’m a beginner.

Using Graphite as the Grafana data source.

Test Data
(would love to get the time between these two events but first thing first) 20 epochTime

servers.object001.config 70 epochTime

I just want a bar that says 50, but that is not to be.

On A: servers | Object001 | build

On B: servers | Object001 | config

on C: Functions | diffSeries(#B,#A)

Draw Mode: Bars

X-Axis: Series

No matter the value setting, it was never 50.

Min: 20

Max: 70

Total: 90

Also tried just using this query, with same results.


So now I’m not only frustrated but my pride is a little bruised. Any help would be greatly appreciated.