This script will add golden hour times to a Google calendar.
This will enter an entire year at a time. Change the YEAR constant in the script to the current year.
This requires a credentials.json file in the same directory as the script. It can be created following these instructions:
https://developers.google.com/calendar/api/quickstart/python
There is no way to bulk delete these entries in Google calendar itself that I can figure out. The script could be modified to delete them with the API.