AM Calendar change at business unit level

Hi,

We want to change the AM calendar at BU level. Somehow in the past, we are setup to use different calendar for AM Vs. GL but PeopleSoft don't allow to do this so don't know how was it done...but obviously older version were allowing it to do so. Now whenever we need to modify something in BU setup at AM level, we need to do it through SQL script which is not a good option as it pop-up an error that your calendar need to be changed.

Now we want to change the calendar same as GL calendar. I want to know if it can impact us in any way.