This is a simple way to make a public web view of a PagerDuty on-call schedule, given the URL of the iCal download found in the export menu. To use, construct a URL like so:
https://martindstone.github.io/PDcal/index.html?iCalURL=XXXX
replacing XXXX with the URL found in Configuration > Schedules > Export > iCalendar file > Everyone. Or, for a much easier way of doing this directly on the browser, see the handy bookmarklet at: