Google + Microsoft calendars
Google Calendar and Outlook sync without duplicate-event chaos
Syncing Google Workspace and Microsoft 365 can make availability easier to see, but simple copy-based synchronization can create a second problem: nobody knows which event is the real one.
What calendar sync usually does well
Basic sync is useful for showing busy time across accounts and reducing accidental double booking. It can be enough when the goal is simply “block my work calendar when my personal calendar is busy.”
Where two-way sync gets complicated
Problems appear when both systems can edit the same logical meeting. An Outlook copy changes, Google updates, a sync service sees the Google change and writes back to Outlook, or an assistant edits the wrong copy. Attendees, descriptions, conferencing links, and recurrence exceptions can drift apart.
Define ownership before synchronization
For every logical meeting, decide which provider owns the authoritative record. Other systems can expose availability or linked context without pretending every copy has equal authority.
Use provider IDs and revisions
A production sync system should retain provider event IDs, revision or ETag information, the last observed payload hash, and the origin of the most recent mutation. Those details make it possible to prevent Google → Outlook → Google update loops.
Normalize time zones before comparing events
The same event can appear different when providers store or display time zones differently. Compare normalized instants while retaining the original event time-zone context, especially around daylight-saving transitions and recurring meetings.
Do not assume Salesforce or CRM events are copies
A CRM event may own the meeting, may simply provide account context, or may be a separate activity record. Treating CRM records as calendar copies without configuration can create bad matches and unsafe edits.
A better model than blind mirroring
CalendarFuse is designed around one canonical event with linked Google, Microsoft, Apple, or CRM records. That allows a user to see the relationship between records without hiding which source owns the meeting. Read the calendar deduplication guide or view the guided demo.