Date Format for Grouped Pivot Table data in Chart - Excel 2016

Hi folks,

I have here what feels like a stuburn rock which I just can't shift :-0 - anyone else come across this and can help me roll this boulder down the hill?

In Excel 2016 I have a date column in my data table formatted as '26/04/2016 12:35:00', I have then used this table to create a pivot table and grouped the data to give daily averages which is then charted. The date is formatted as 26-Apr automatically in both the Pivot table and chart - no mater where I change the format it remains the same (cell format, field settings, axis options with/without linked to source.....) - see the snip below.

Surely we must be able to control this somehow?

Thanks for any help - cheers.

Hi Folks - I'm coming back to this question again as I didn't manage to find a solution last time unfortunately - anyone know how to fix this?

Cheers