Changing FY calendar on one Peoplesoft BU

Hi Team,

Have any of you come across a situation to be changing the FY Calendar for ex: lets say from Oct-Nov to Jan-Dec calendar for one of the Business Units to which data has been posted till date.

What could be the best practice approach to be handling such a situation.?

In case anyone have done this before, please provide your thoughts.

Thanks & Regards,
Sai