Hi Holly,
Thanks for going Pro and welcome to the forums!
I’m sorry your having this problem with the timezones. Let me try to help you with this.
First thing to set your server time properly. Usually the servers follow the summer / winter time, so I suggest to set this to your closest city (and not UTC +/- time).
Then for your events, since UTC based time doesn’t change with summer / winter time (UTC and the difference to UTC time never changes), I reco to set your events to the UTC time. This should also make the times proper when visitors download the iCal file or export it to Google calendar.
Try these settings and let me know how it works out.
Cheers,
Andras