Internet Subscribed Calendar Refresh/Sync RAGE!!!

Hi Charles, I understand the frustration. Internet subscribed calendars in Outlook are not designed for true real-time refresh, and the refresh interval is controlled by the client/service rather than a reliable manual sync button. For calendars that must update immediately, the better option is usually a shared Microsoft 365 calendar, delegated mailbox calendar, or direct account connection instead of ICS subscription. If you must stay with ICS, I would keep the source calendar URL stable, remove and re-add the subscription if it is stale, and use Outlook on the web as a comparison point.