Incorrect time axis units for iris.quickplot.plot

[ajdawson]

When making a 1D plot where time is a coordinate with iris.quickplot.plot the label for the time coordinate is "Time / units", where units is a udunits time unit e.g. days since 1900-01-01 00:00:0.0. However, since the time coordinate will have been translated into date/time for the plot the units part no longer makes sense, and should not be displayed.

An example:

[pelson]

I've been thinking about this recently too. A part of me is tempted to hook the label into the AutoDateFormatter and update the label with something like time / hh:mm, or whichever is (dynamically) chosen by AutoDateFormatter. Equally, it would be just as valuable at this stage for it just to say time and not bother with the units. Thoughts?

[rhattersley]

Equally, it would be just as valuable at this stage for it just to say time and not bother with the units. Thoughts?

If the labels are "absolute times" (e.g. "Jan 17", "8:30am", etc) then I'd ditch the units. But there will also be occasions where we have "relative times" (e.g. a forecast period of 6 hours) so the label would just be "6" and we need the units.

[esc24]

I agree with @rhattersley. is_reference_time() should do the job in iris.quickplot._title().

[ajdawson]

To be clear I was definitely only referring to time coordinates where a reference unit is used, and that are automatically transformed to absolute dates/times. Other times should preserve units.