Hier habe ich lediglich den privaten Link zum Google Calendar eingefügt (Privat-Adresse im iCal Format):
https://calendar.google.com/calendar/ical/christian.zumbrunnen%40gmail.com/private-563b41834538c6712f28cb8598721bc3/basic.ics
https://calendar.google.com/calendar/ical/christian.zumbrunnen%40gmail.com/public/basic.ics
https://calendar.google.com/calendar/embed?src=christian.zumbrunnen%40gmail.com&ctz=Europe%2FZurich