Feature: Google Calendar Sync - Button + by product/ category.

[johannesmutter]

• Add a button to the calendar to initiate a forced sync with the Google Calendar. Why? E.g. when switching or editing the google Calendar only newly added appointments will appear (even ones in the future). And sometimes updates to appointments don’t get synced. Maybe do a cron job something similar?
• Add ability to sync appointments by category or on a product level with a specific Google Calendar ID. For all products/ product categories where no specific category is defined: use the one defined in the WooCommerce Appointments settings.

[Željan Topić]

a) Forced sync is done automatically every day, just in case. Manual incremental sync is done each hour, just in case. And there is also live incremental sync, which is done instantly, when your site is under SSL and is configured correctly with developer and search console.

b) It did work like this before, but we got so many complaints, we now allow sync to one calendar only. We'll add some filters to allow advanced sync you suggested - but with custom code.