Given a subscribed calendar with a url like
https://example.com/example.ics
To force Google Calendar to refresh and reload the contents right now, unsubscribe from the calendar and subscribe to a new calendar with a URL like
https://example.com/example.ics#1
Adding the anchor tag will force Google Calendar to think of it as a new calendar
Many people who come to this gist are not looking for a one time forced refresh but instead to refresh recurringly. If that's you, you should check out @derekantrican 's Google App Script
https://github.com/derekantrican/GAS-ICS-Sync
Which can refresh a calendar automatically every N minutes
Thanks to @rattrayalex for pointing people to this script
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CALSCALE:GREGORIAN
VERSION:2.0
X-WR-CALNAME:Test
METHOD:PUBLISH
PRODID:-//Apple Inc.//macOS 15.1//EN
BEGIN:VTIMEZONE
TZID:America/Chicago
BEGIN:DAYLIGHT
TZOFFSETFROM:-0600
DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
TZNAME:CDT
TZOFFSETTO:-0500
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0500
DTSTART:20071104T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
TZNAME:CST
TZOFFSETTO:-0600
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CREATED:20241016T184536Z
DTEND;TZID=America/Chicago:20241016T203000
TRANSP:OPAQUE
UID:D07D5FEA-F632-4984-A93C-6417F0251E48
X-APPLE-CREATOR-IDENTITY:com.apple.calendar
X-APPLE-CREATOR-TEAM-IDENTITY:0000000000
SUMMARY:Test
DTSTART;TZID=America/Chicago:20241016T201500
DTSTAMP:20241016T184618Z
LAST-MODIFIED:20241016T184536Z
SEQUENCE:0
BEGIN:VALARM
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ACTION:DISPLAY
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