Pivot Table Filter Formatting Question

Hi, i have attached a sample with a simple example.

in Pivot Tab, my filter is in B1 and i choose 01/08/2017. But at first its at "dd-mm-yyyy" format. I wan it to show as "mm'yy". Hence i format it to "mmm/yy". I thot everything is in order until i choose another date (example, 01-06-2017) it should show Jun'17 coz i already format it to "mmm'yy". HOwever, it show 01-06-2017 again! When i choose 01/08/2017. It show Aug'17. When i choose 01/06/2017 or 01/07/2017, it show "dd-mm-yyyy"

How to solve this? Also, another one can tell me how to make the Drop down list appear as "mmm'yy" instead of DD-mm-yyyy??

you want mm'yy or mmm'yy ?
the way is the same

(or I misunderstood)

pt-fieldformat.jpg

Welcome