I recently had an issue with calendar syncing, you can see the thread here: https://community.smartsheet.com/discussion/resyncing-google-calendar
As you can see in the response to the thread that a resync option isn't available. I had also had a conversation with Smartsheet support prior to getting a response on the forums. They also said the same thing, resyncing to an existing calendar is not possible.
This leaves me with two options. Continue down the same path and every time a calendar loses its sync, create a new one, delete the old and then share it with everyone that needs it. This is problematic when you have hundreds of people you need to share the calendar with. Even when I delete the calendar and choose (delete for everyone) the calendar itself does not delete off any employees that it was shared with. It stays there in the state it was from the last successful sync.
Then when I share the new calendar with the same name, employees tend to get confused on which is the current calendar and have double entries. In theory this is not a big issue but when you are dealing with this amount of people it becomes a hassle having to deal with it.
The second option I have is to use the iCal feature. This is nice because the link is always the same and I do not have to worry about resyncing creating a new calendar and all of the above. However, the initial setup of this is far more work than the former. When you share a calendar with Gmail recipients it automatically populates their calendar list. When using iCal you have to rely on the user going through the steps of adding a calendar via URL.
Again, in theory not a big deal. However, when you are dealing with this amount of people it becomes a hassle when a good 15%-20% have issues that either relate to lack of technical knowledge or a totally different view setting within google that renders my step by step instructions invalid. I then have to manually add this for multiple people.
There are two suggestions I would like to make. The first would be to add an option when publishing to Google Calendar to choose an existing calendar to sync to or create an existing calendar. This would eliminate the problem of having to create a new calendar anytime there is a loss of connection.
It also allows you to sync multiple sheets to a single calendar (something I do not see possible at the moment). This would be beneficial for us. For example we use smartsheet to track our employee vacations. We then populate that to a calendar that everyone needs access to to view. We also have an events announcement that goes out via email that we would like to just integrate into smartsheet and sync to the vacation calendar. That is not possible via iCal or Publish to Google calendar.
So a new calendar have to be created and then all issues described above double. It would be nice to be able to sync multiple sheets to a calendar to eliminate what becomes a convoluted spiders web of management.
If anything I described above is inaccurate, please let me know.