For a site, I went into schedule and created a printable version of the calendar, which opened a new window displaying the PDF file and the following URL:
I was then able to open a different browser and paste in this URL, and was able to generate the PDF. I then changed the URL to display a different month, and then entered that URL. I was able to pull up a calendar of a different month from my site. I then tried to replace the site id with the site id from another site, and was able to pull up a schedule from that site as well.