Pivot Automation: Remove earliest date and add 1 date (Rows)

I would like to use VBA to go through multiple pivot tables that I specifiy and change the month that is in the Rows field to take out the old month and add a new month.

Pivot table is set up with the dates in the rows because it controls a historical trend chart. Each month, I would like to just push a button or use a drop down to uncheck the earliest date and check the next date in the list (please quickly view my attached picture if you can)

Any ideas on how to do this easily?