A subscribed (WebDAV) calendar on my Mac isn’t showing on iPhone/iPad
If you subscribed to a public calendar (WebDAV / .ics) in BusyCal on your Mac and want it to appear on iPhone/iPad, it won’t automatically sync through all services.
Fix: Sync the subscription through iCloud (recommended)
Follow the step-by-step guide here:
Alternative
If you’re not syncing through iCloud, you can subscribe directly on iOS in BusyCal: