Your Google Calendar contains really private information. It tells any reader where and when you’ll be next and potentially why and with whom you’re meeting. If made public or leaked, your whole agenda or specific entries become a security risk. Even past entries can be used to derive future appointments even before they’re on your calendar. Is your Google Calendar public or private?
Your Google Calendar and events are private to you and Google Services by default. You may share individual entries or your entire calendar with other Google accounts or via email. Calendars can be set as public if needed.
Before you read on, go review your Google Calendar settings by clicking here. Pay special attention to the sections “Access permissions” and “Share with specific people” on each calendar. Leave the settings tab or window open. We’ll walk through the settings in this article.
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Google Calendar Privacy
Google Calendar privacy differs depending on whether you’re using it personally or for work.
For Personal Google Calendar Users
Many users have been managing their personal calendar and household agendas since July 2009 when Google first released its online calendar. That’s a lot of calendar data accumulated over the years. Generally, if you’ve not poked around inside the default visibility settings, your configurations should be keeping your event details private.
Even though your calendar is set to private, your data is shared with other Google Services.
You’ve likely seen that birthdays and anniversaries from your Google Contacts show up Google Calendar. Or you may have noticed that Google Maps points out destinations based on the location field from Google Calendars. Cross-service data sharing is a helpful feature with some potential downsides.
Google trains its machine learning and artificial intelligence using your data including your online calendar.
For example, the Events from Gmail feature scans the contents of your emails for restaurant reservations, flight itineraries, etc. The algorithm then adds these to your Google Calendar. While processing this feature, the AI reviews emails for dates like doctor’s appointments, insurance meetings, and scheduled parent-teacher conferences.
Carefully consider the trade-off of convenience and privacy.
For Google Workspace (G Suite) Calendar Users
Businesses can subscribe to Google Workspace (formerly G Suite), a competitor to Microsoft’s Office applications. For their paying customers, Google states in their privacy FAQ that data put into Google Workspace is not owned or used by Google for any purpose. This implies that Google Workspace Calendar users have better trust that individual and group calendars along with event details are handled with more care and privacy.
However, Google Workspace “super administrators” have a bit more control over all of the services including work calendars. The calendar help documentation has a section called “Super administrators have access to all calendars”.
This makes sense for a business environment where all the data belongs to the organization. In this case, privacy from Google is better, but your calendar privacy is open to other employees with the right access.
Google Calendars provide several sharing settings. It’s always best practice to set sharing options to the least amount of information with the fewest number of contacts at the lowest access level necessary. The more information you share the larger your threat surface or the number of ways an attacker has to get to more of your data.
You’re most likely familiar with sharing individual events when you schedule meetings or appointments between attendees. The initial meeting invitation and subsequent updates are usually transmitted over plain-text email.
As we discussed in our previous article, “How Do I Know If My Email Has Been Hacked? Follow These 6 Tests“, email is typically the least-secure communication methods. Calendar entries sent across email are not encrypted before added to the body or as an attachment to an email.
Some email and calendaring services implement secure handling of event sharing. Google Calendar does this well only when the invitation stays within the Google ecosystem.
Entries shared with non-Google email addresses are sent via unencrypted email to those contacts.
Here’s an example of a via-email calendar entry. What’s the visibility of my bank balance in the below email code? ⬇️ Do you see it?
In addition to my sensitive financial information, you can see the event guests, time, and location of my meeting. If this was a personal calendar entry, my Gmail account and my invited recipients’ Gmail account would be snooping on personal matters.
Both the sending and receiving email services must implement secure transmission to protect unencrypted emails; otherwise, any calendar data within an email can be easily read.
In addition to the interception, your shared calendar events might be leaked if your invitees’ account is breached. Your Google Calendar appointment is now copied to their agenda. If you delete the appointment from your calendar, your data and history are now outside your control since there’s no direct link back to your certain events.
Sharing your Google Calendar as a whole can make sense when you and your collaborator are both using Google accounts or are in the same business Google Workspace organization. Doing it this way allows for securely limiting event details sharing while allowing collaborators to make changes in real-time
You may grant another account the ability to only see free/busy time, view all entry details, edit calendar entries, and even manage the sharing settings for the calendar. Here again, it’s best practice to use the least-privileged visibility settings necessary.
While account-to-account calendar sharing provides better control of your data, be mindful that events copied off your calendar remove your control of the information within the entries.
Best Practices for Public Google Calendars
There are some limited instances where hosting a public calendar is a good option.
A good example might include the ability to rapidly make changes to conference events on a calendar published through your website’s home page. Public or semi-private events often include many attendees and by their nature possess less privacy risk. This is where the trade-off of convenience might outweigh privacy.
The best practice is to create a new calendar for public events and limit calendar usage to a specific occasion or purpose. Sharing this calendar publicly or semi-privately through a special, shareable link provides compartmentailization
Title the calendar clearly to ensure its use is clear. For our previous example, “Company Conference 2020” or “Annual Public Trade Show”.
Deleting or unsharing old calendars after they are no longer needed human-proofs public calendars. You wouldn’t want to accidentally add a meeting like “IPO Kick-Off Meeting” to that public trade show calendar view.
Google Calendar provides a lot of functionality. The calendar along with other functions within the paid, business-level productivity suite hold independently-audited ISO 27001 certification.
Individual, free-tier Google Calendar users might be satisfied with the default settings Google provides over your sensitive calendar entries. Personal responsibility of your data is increasingly important when you choose a big tech company to hold your data free of charge.
How do you delete someone from your calendar? Most calendar platforms offering full-calendar sharing provide settings to add and delete collaborators. Go to your calender’s settings. In the section labeled “sharing”, click the removal icon beside users you wish to revoke access. You may also have a “private” option for the calendar.
How do I protect my Google Calendar? Protect your Google Calendar by carefully adjusting calendar and event settings where options might provide access to other accounts or the public. Consider switching to Google Workspaces’s Calendar or a privacy-respecting productivity suite like Disroot, Mailfence, or ProtonMail.
What is a secure & private alternative to Google Calendar? Many privacy-respecting email providers offer calendaring within their productivity suite. PrivacyTools.io lists several that include secure and private alternatives to Google Calendars.