Google Calendars work seamlessly with which of the following?

Google Calendars are designed to integrate seamlessly with Gmail, enhancing the user experience by allowing users to easily access their calendar directly from their email platform. For instance, when you receive an event invitation via Gmail, you can respond to it without needing to switch applications. This integration facilitates the automatic addition of events shown in emails to your Google Calendar, streamlining event management and scheduling for users.

Other choices, while they might have some level of compatibility or ability to interact with Google Calendar, do not offer the same level of seamless integration as Gmail does. For example, while Microsoft Outlook can connect to Google Calendar, users may experience additional steps in setting up this connection compared to the direct link Gmail provides. Similarly, Yahoo Mail and Facebook Messenger do not have strong inherent integration with Google Calendar, making managing events and appointments less efficient.