I have a daily bar graph within an emoncms dashboard that displays differently depending on if emoncms is logged in or not.
When the dashboard is displayed without logging in to emoncms, interpolation of data reflecting a daily timeslot aligned to midnight GMT (11:00 local time) is evident. This is very evident in the right most set of bars in the image below.

When the dashboard is displayed when logged in to emoncms, the bars on the graph and the associated forecast data is consistant with a dialy timeslot alligned with midnight local time.

The only difference between the above two images was the logged in status of emoncms when displaying the dashboard. Note that the forecast data (the non shaded yellow bars) differs across the entire graph.