If you’re looking for a real sync solution you may try our app DAVdroid. You need to set up a CalDAV server first. Then you will be able to synchronize your calendars in two way. DAVdroid is open source and it published under GPL and we also sell it in the Google Play store, because it was and is very hard work to write and maintain it.
Scripting a sync.
Syncing local files works nicely but instead of polling I’d like to trigger an immediate refresh with ICSdroid when I’ve updated my .ics file.
Is this already possible with intents or some such?
you can use the swipe down gesture in the overview where your calendar is listed then it will make a forced refresh