Hi @d82k
I have been working on and off on a project along these exact lines. There are some challenges since Google wants to remember every calendar entry, the parsing gets progressively more difficult on the core as your history of events grows. I haven’t given up, but I do see some problems. The solution might be to move away from Google, but that was my first choice too.
I have also been working on getting vcal/ical entries into a core for similar purposes.
Have you also seen this:
I wrote code over there to control 4 relays from the Spark cloud with start times and durations. I will be writing a web interface for it as well. It is a whole lot simpler and less ambitious, but it works great right now.