Problem: Regular pivot tables use the Custom Lists dialog to automatically sort months into Jan, Feb, Mar sequence. Power Pivot doesn't seem to be aware of Custom Lists and sorts into the alphabetic sequence of Apr, Aug, Dec, Feb, Jan, Jul, Jun, Mar. May, Nov, Oct, Sep.
Strategy: There is an eight-click workaround in the Excel interface, but by your second week of using Power Pivot, you will resign yourself to the fact that you need to have fields in your model called MonthNumber and MonthName.
Click in the MonthName column. On the Power Pivot ribbon, go to the Home Tab. Select the Sort By Column icon. In the Sort by Column dialog, indicate that you want to Sort MonthName by MonthNo.
- It is annoying, but you will eventually accept this extra step.