This calendar is approximate and busy positive: where it says I'm busy, then it's probably not worth asking to arrange an appointment; elsewhere, I might still be unavailable but it's reasonable to try.
You can reach this calendar in several ways:
Anyone using the University of Edinburgh diary service, through either Microsoft Outlook or Office 365, can link to this as a shared calendar for "STARK Ian".
In Google Calendar it's shared under my email address Ian.Stark@ed.ac.uk.
Google also present it as a CalDAV server and an iCalendar file.
Please note that while synchronization between these sources is automated, it does involve string and sealing-wax so may be delayed or imprecise.