My ICAL file from Google Calendar doesn't recognize the timezone offset for certain events. I live in the Central timezone and events that I've created show up fine. Events that have been created by somebody in another timezone show up without
the timezone offset. Looking at the ICAL file, it appears that the TZID that Google provides is being ignored.
An example of an event that I've created:
This shows up normally as 10:00am - 11:00am.
An example from somebody in Eastern time:
This shows up as 3:00pm - 3:30pm instead of 2:00pm - 2:30pm.
And, to be thorough, here is the Timezone info that Google provides for America/New_York: