Custom calendar file location

Can we change the location of the calendar files. I have made changes to the calendar for my national, but the location of the calendar file is in the installation file structure. The software was installed by our sysadmin and as such I do not have write access. Running on windows I would think a good location would be defined by the environment variable $LOCALAPPDATA\ganttpoject\calendars\

Unfortunately I do not know the equivalent for linux and macos

Dave