Google Calendar as blockers

Your Google Calendar appears as “Busy (google)” in your work calendar, without a Google password or OAuth: Capycal reads the calendar’s secret iCal address. The same works with Outlook.com and any other service that publishes a calendar as an .ics address. See Calendar feeds for where to find the address.

In the app: in Google Calendar, copy Settings for my calendars, the calendar, Integrate calendar, Secret address in iCal format. Then in Capycal Add Sync…, Add Calendar Feed… below the calendars, paste the address into Feed address and Continue; pick the work calendar as the target and Busy blocker. In the sync’s From, set Check every to Custom and 30m.

In the config:

[daemon]
log_level = "info"

[accounts.work]
url = "https://caldav.work.example.com/"
username = "alice"
password = { env = "CAPYCAL_WORK_PASSWORD" }

# The secret address, kept out of the config file
[calendars.google]
ics_url = { env = "CAPYCAL_GOOGLE_FEED" }

[calendars.work]
account = "work"
url = "https://caldav.work.example.com/calendars/alice/default/"

[syncs.google-to-work]
source = "google"
target = "work"
# Google refreshes the feed only every few hours
interval = "30m"

transforms = [
  { field = "SUMMARY", action = "set_field", value = "Busy ({{source_name}})" },
]

What happens:

• Every 30 minutes Capycal downloads the feed and copies new, changed and removed events. Google itself updates the feed with a delay of several hours, so a new private appointment can take that long to block your work calendar. For changes within minutes, read Google through Calendar.app on a Mac instead (Calendar.app to Nextcloud).
• Without fields, only times, recurrence, status and free/busy are copied; an event you marked as “free” in Google stays free.
• The feed is read-only: Capycal never writes to Google. A feed cannot be the target of a sync.
• Anyone with the secret address can read the calendar. If it leaks, Reset it in Google Calendar and enter the new one.