Tutorial: Troubleshooting Tab Sync When Events Do Not Appear

Events missing? Start here.

Tab Sync reads calendar data directly from open browser tabs. It is fast, requires no credentials, and works across any web-based calendar. But it depends on the tab being in the right state. If events are not showing up in manyCalendars, the cause is almost always one of four things.

Cause 1: The calendar tab is not fully loaded

Symptom: manyCalendars shows zero events from a calendar that definitely has meetings on it.

Why it happens: The browser tab may have been suspended by the browser's memory management (common when you have many tabs open), or the page may still be loading a spinner.

Fix: Click on the calendar tab to bring it to the foreground. Wait for it to fully load. You should see your events rendered on screen. Then return to manyCalendars and trigger a refresh. Events should appear within seconds.

Cause 2: The calendar is in month view instead of week view

Symptom: Some events appear, but many are missing. Particularly shorter meetings or events later in the day.

Why it happens: In month view, most calendar applications collapse or hide events that do not fit in the day cell. They might show "3 more" instead of rendering each event. manyCalendars can only sync what is actually rendered in the DOM.

Fix: Switch the calendar tab to week view or day view. This forces the calendar to render all events for the visible date range with full detail. manyCalendars will pick up significantly more data from a week view than a month view.

Cause 3: Events are outside the visible date range

Symptom: Events from the current week appear, but next week is empty even though you know meetings are scheduled.

Why it happens: Tab Sync reads what is currently rendered on screen. If the calendar tab is showing October 14-18 and you are looking for events on October 21, those events have not been rendered yet.

Fix: Navigate the calendar tab forward to the date range you need. Let it load, then refresh manyCalendars. For best coverage, keep the source calendar on the current week and sync again regularly. manyCalendars retains previously synced events, so navigating forward and back builds up a fuller picture over time.

Cause 4: Private events are hidden by default

Symptom: Most events appear, but a few that you know exist are consistently missing.

Why it happens: Some calendar platforms render private or confidential events differently, sometimes omitting them from the standard view for non-owners. If you are viewing a shared calendar, private events may not render at all.

Fix: Check the calendar's privacy settings. If possible, view the calendar as the owner (your own account) rather than through a shared view. For events you own, mark them as "default" visibility rather than "private" if you want them to appear in manyCalendars.

When to use ICS feeds instead

Tab Sync works best for calendars where you have a browser tab open anyway. But if you find yourself constantly troubleshooting a specific calendar, consider switching to an ICS feed for that source. ICS feeds pull data from the server directly, so they are not affected by tab state, view mode, or DOM rendering issues.

The tradeoff: ICS feeds can lag by minutes to hours depending on the provider's refresh interval. Tab Sync is real-time. Choose based on what matters more for that specific calendar: reliability or freshness.

Still stuck? The answer might be simpler than you think. Install manyCalendars and the setup wizard walks you through each calendar source, confirming that events are flowing before you finish configuration. No guesswork required.