Is it a Virus?
✔ NO - Safe
Must be located in C:\Program Files\Calendar Sync\calendar-sync.exe
Warning
Active sync processes may run in background
Each provider connection runs as a separate worker
Can I Disable?
✔ YES
You can disable or pause syncing from settings without uninstalling
What is calendar-sync.exe?
calendar-sync.exe is the background calendar synchronization engine for the Calendar Sync product. It coordinates events between your local calendar store and cloud providers, monitors changes, and applies updates to keep data in sync across devices and apps.
The service authenticates with each provider, polls or receives push updates, resolves conflicts, and writes changes to the local cache. It uses secure storage for tokens and honors user preferences to minimize data traffic.
Quick Fact: Calendar Sync supports Google Calendar, Microsoft 365/Outlook, and iCal feeds with conflict resolution and offline changes handling.
Types of Calendar Sync Processes
- Background Sync Service: Runs continuously to synchronize events between providers and the local calendar store
- UI/Configuration: Shows status, logs, and settings in the calendar-sync app UI
- Provider Adapter: Handles API calls to Google, Microsoft, and iCal sources
- Update Agent: Propagates changes from one source to others with conflict resolution
Is calendar-sync.exe Safe?
Yes, calendar-sync.exe is safe when it's the legitimate file from Calendar Sync, downloaded from official sources or installed by your organization.
Is calendar-sync.exe a Virus or Malware?
The real calendar-sync.exe is NOT a virus. Malicious software may mimic names; verify file location and signature to be safe.
How to Tell if calendar-sync.exe is Legitimate or Malware
- File Location:: Must be in
C:\Program Files\Calendar Sync\calendar-sync.exe or C:\Program Files (x86)\Calendar Sync\calendar-sync.exe. Any other location is suspicious.
- Digital Signature:: Right-click calendar-sync.exe in File Explorer → Properties → Digital Signatures. Look for a signature from Calendar Sync, Inc..
- Resource Usage:: Normal usage is around 1-12% CPU and 40-180 MB memory per active sync cycle. Unusually high usage when idle is suspicious.
- Behavior:: Calendar Sync should only run when syncing or when the UI is open. Persistent background activity when idle may indicate malware.
Red Flags: If calendar-sync.exe is found outside Program Files, lacks a valid signature, runs when idle, or produces unknown network connections, run a full antivirus scan and verify from a trusted installer source.
Why Is calendar-sync.exe Running on My PC?
calendar-sync.exe runs to coordinate calendar data across providers. It may operate even when the main UI is closed to keep data in sync and ready for quick updates.
Reasons it's running:
- Active Calendar Synchronization: You have ongoing sync with one or more providers, so the service remains active to monitor changes.
- Background Connector: Provider adapters run in the background to receive updates and push changes to other calendars.
- Startup Launch: Calendar Sync starts with Windows or user login to ensure calendars are up to date on startup.
- Offline to Online Push: Local edits made while offline are queued and synced once connectivity is restored.
- Conflict Resolution: The app runs to reconcile conflicting edits across devices, ensuring consistent event data.
Can I Disable or Remove calendar-sync.exe?
Yes, you can disable calendar-sync.exe. You can pause syncing or uninstall Calendar Sync if you no longer need it.
How to Stop calendar-sync.exe
- Pause from UI: Open the Calendar Sync UI and click Pause or Stop Sync. This prevents new changes from being sent.
- Exit UI: Close the calendar-sync window completely to stop the UI from running.
- End Background Service: Open Windows Task Manager, find calendar-sync-service.exe, right-click → End Task
- Disable Startup: Task Manager → Startup tab → disable Calendar Sync
- Stop Auto-Start of UI: If installed as a startup item, remove the shortcut from Startup folder
How to Uninstall Calendar Sync
- ✔ Windows Settings → Apps → Apps & Features → Calendar Sync → Uninstall
- ✔ Control Panel → Programs → Uninstall a program → Calendar Sync → Uninstall
- ✔ Restart the computer after uninstall
Common Problems: Sync Issues or Performance
If calendar-sync.exe behaves unexpectedly or uses resources excessively, review these common problems and fixes.
Common Causes & Solutions
- Conflicting edits across devices: Review recent edits and resolve conflicts in the UI; ensure automatic conflict resolution is enabled.
- Authentication failed: Re-authenticate providers in the UI under Accounts; refresh tokens if prompted.
- Network issues: Verify internet connectivity; ensure firewall allows outbound connections to provider APIs.
- Stale cache: Clear local cache in the UI or delete cache folder at C:\Users\Public\CalendarSync\cache (then restart).
- Old app version: Update to the latest Calendar Sync version from the official site or app store.
- Resource-heavy providers: Limit the number of providers or reduce sync frequency in advanced settings.
Quick Fixes:
1. Quick Fixes:
2. 1. Open UI and check for authentication prompts; re-authenticate as needed
3. Restart the sync service from Task Manager
4. Verify network connectivity and firewall rules
5. Update to the latest Calendar Sync version
6. Clear local cache and resync calendars
Frequently Asked Questions
Is calendar-sync safe?
Yes. Calendar Sync is designed to securely synchronize calendar data across providers. Ensure you install from official sources and review provider permissions.
Why is calendar-sync.exe using memory?
The sync engine maintains provider connections, caches events, and resolves conflicts. Moderate memory use is expected; heavy usage may indicate many active calendars or large event histories.
Can I disable calendar-sync from starting automatically?
Yes. Use Task Manager → Startup to disable Calendar Sync, or disable the service/daemon from the app settings.
Where is my calendar data stored?
Calendar data is stored in the local calendar store managed by the Calendar Sync app; configuration and cached event data are in C:\Users\Public\CalendarSync and in the app's data folders.
Which calendars are supported?
Calendar Sync supports Google Calendar, Microsoft 365/Outlook, iCal feeds, and local ICS calendars. Check provider adapters in the UI for specifics.
How do I fix authentication errors?
Open the UI, go to Accounts, re-authenticate the provider, and refresh tokens. If problems persist, re-install or contact support with logs.