How do I publish more than the default (2 months) public free busy
information for a calendar created in a public folder?

Using current Exchange (SP1) and Outlook (2003-SP2) clients how do I change
the length of free busy information to 14 months for a calendar in a public
folder.  I am creating agency and group calendars to make visible holidays,
meetings and events at those levels.  I'm also adding these calendars to
group schedules to aid in setting up meetings of those groups.  I'm only
getting 2 months (approx) of free busy information from the public folder
calendars.  I'd like to see at least a years worth for long term meeting
planning.  Where do I find the settings for free busy for each calendar?  &
where do I find the default setting for new calendars created in the future?