Switching Factory Calendars

Hello,

I have recently discovered that we are using the wrong factory calendar for both SD and PM. The wrong one may have been used to generate the scheduled work hours in HR too. We have 2 different custom calendars that need to be used - neither is currently used. One was designed for our 24/7 treatment plant operations. The other was for designed for HR, SD, and equipment with maintenance that is on a typical M-F, excluding holidays. Our current configuration is that all equipment is in one plant.

Would there be any issues switching the calenders in SPRO for SD and PM? After reading many other forum posts, I understand that only one calendar may be assigned to a plant. Is there any problems with using a different calendar in the maintenance plans than the plant calendar?

Any help or advice would be appreciated.

Thanks.