One-Way vs Two-Way Calendar Sync

Most calendar sync tools offer a simple proposition: events on Calendar A appear on Calendar B, and vice versa. That's two-way sync, and it's the default for good reason - it prevents double-booking across all your calendars.

But sometimes you need more control. Sometimes you want events to flow in only one direction.

The Three Sync Modes

Sync My Calendars lets you configure each calendar independently:

• Two-Way (Default) - Events sync in both directions. This calendar sends events out and receives events from other calendars.
• Send Only - This calendar's events replicate to your other calendars, but nothing gets added to it. The calendar stays "clean" - untouched by syncmycalendars.com.
• Receive Only - This calendar receives events from your other calendars, but its own events don't replicate anywhere. It's a destination, not a source.

Why Would You Want One-Way Sync?

Keep a Calendar Untouched

Maybe your family shares a Google calendar for kids' activities, vacations, and household events. You want your work calendar to show these family commitments (so you don't schedule a client call during your daughter's recital). But you don't want work meetings cluttering up the family calendar that everyone sees.

Solution: Set the family calendar to Send Only. Family events flow to your work calendar. Work events stay off the family calendar.

Create a "Master View" Calendar

You might want one calendar that shows everything - a consolidated view of all your commitments across work, personal, and side projects. But you don't want this aggregation calendar to push events back to your other calendars.

Solution: Set your master calendar to Receive Only. It collects events from everywhere but doesn't send anything back.

Executive Assistant Aggregation

EAs managing multiple executives can create a single calendar that receives events from all principals' calendars. This gives one place to check for conflicts when scheduling. The principals' calendars stay clean - they only see their own meetings, not each other's.

Solution: Set each executive's calendar to Send Only toward the EA's aggregation calendar, which is set to Receive Only.

Where It Gets Interesting: Three or More Calendars

With two calendars, sync direction is straightforward. With three or more, you can create sophisticated flows.

Example: Work + Personal + Family

Say you have:

• Work calendar (Outlook) - where colleagues schedule meetings
• Personal calendar (Gmail) - your private appointments
• Family calendar (shared Google) - visible to spouse and kids

You might configure:

• Work: Two-Way (you need to see personal on work and work on personal)
• Personal: Two-Way (you need to see personal on work and work on personal)
• Family: Receive Only (it's a shared view for the household, not a source of events for your other calendars)

Result: Your work and personal calendar shows work + personal. Your family calendar shows when you're busy (for household planning) without being cluttered by every work meeting.

Example: Consultant with Firm + Multiple Clients

A consultant with a firm calendar and two client calendars might want:

• Firm calendar: Two-Way (the "home base" that sees and shares everything)
• Client A calendar: Send Only (Client A's meetings appear on firm calendar, but firm meetings don't clutter the client calendar)
• Client B calendar: Send Only (same logic)

Now the consultant's firm calendar shows all commitments across all clients. But neither client sees the other client's projects - and neither client calendar gets polluted with internal firm meetings.

Add Private Sync to this setup, and even the meeting titles stay confidential across client boundaries.

How to Configure Sync Direction

In your Sync My Calendars dashboard, each connected calendar has a sync direction dropdown:

1. Log in to your account
2. Find the calendar you want to configure
3. Select the sync direction: Two-Way, Send Only, or Receive Only
4. Changes take effect on the next sync cycle (within 3 minutes)

You can change this setting anytime. If you switch a calendar from Send Only to Two-Way, events from your other calendars will begin replicating to it on the next sync.

Combining with Private Sync

Sync direction and Private Sync are independent settings that work together:

• Send Only + Private Sync: This calendar's events appear as anonymous time blocks on other calendars, and nothing syncs back to it.
• Receive Only + Private Sync: This calendar receives anonymous time blocks from your other calendars - a privacy-preserving master view.

This combination is powerful for co-parenting, where you might want a shared calendar that shows both parents' availability without revealing the details of either parent's personal life.

The Default: Two-Way Sync

If you're not sure what you need, stick with the default. Two-way sync on all calendars is the simplest setup and prevents double-booking across all your accounts.

Sync direction is there when you need finer control - and now you know it's available.