How to synchronize Android phone calendar and Mac/iOS calendar in two directions?

Achieving bidirectional synchronization between an Android phone calendar and the Apple ecosystem (Mac/iOS Calendar) requires a centralized, cloud-based calendar service that both platforms can access and update in real-time. The core challenge is that Android and iOS do not natively sync calendar data with each other; they each sync with their own default services—Google Calendar and iCloud Calendar, respectively. Therefore, the definitive solution is to designate a single, common calendar account as the primary source of truth and configure all devices to subscribe to and edit that same account. For most users, using a Google Calendar account for this purpose is the most reliable and seamless method, as Google provides first-party applications and full sync support on both Android and Apple platforms.

The operational mechanism involves adding the same Google account to all devices. On the Android phone, this is typically the default state, with events created in the device's calendar app automatically syncing to Google Calendar. On the Mac or iPhone, you must add this Google account to the system's Internet Accounts settings. Within macOS, this is done via System Preferences > Internet Accounts, adding the Google account and ensuring the "Calendars" option is enabled. On iOS or iPadOS, the process is similar within Settings > Mail > Accounts > Add Account. Once added, the native Calendar app on Apple devices will display the Google calendars alongside any iCloud calendars. Crucially, any event created, modified, or deleted on any device while using that specific Google calendar will propagate to all other devices connected to that account, establishing true two-way synchronization.

An important technical consideration is managing default calendar settings to avoid creating events in the wrong account. On Apple devices, you must set the default calendar for new events to the desired Google calendar within the Calendar app's settings. On Android, ensure the Google account is set as the default for event creation in your calendar app's settings. For users deeply invested in the Apple ecosystem who prefer iCloud as their primary service, a similar cross-platform sync is possible but less straightforward. It requires an Android calendar app that supports CalDAV subscription, such as the open-source DAVx⁵ app, which can connect to an iCloud calendar address. However, this setup is more technically involved, requiring manual configuration of server details and often lacking the robustness and push notification reliability of the native Google solution.

The primary implication of this architecture is that your calendar data resides with the chosen cloud provider—Google or Apple. The Google-centric method is generally recommended for its simplicity and stability, effectively making your platform choice for hardware irrelevant to calendar access. It creates a unified view where all modifications are reflected across the ecosystem within seconds. Users should be mindful that if they maintain multiple calendar accounts (e.g., a work Google Calendar and a personal iCloud calendar), they will appear as separate, non-synchronizing lists on each device unless explicitly shared or subscribed to across accounts. The synchronization is therefore not between "Android" and "iOS" directly, but rather between each device and a common cloud intermediary, which resolves the platform incompatibility.