Where your calendar data lives in manyCalendars

“Local” and “private” are easy words to stretch until they stop being useful. The direct answer for manyCalendars depends on which part of the product you use.

Local extension mode

The extension reads supported calendar pages inside a browser profile where you are already signed in. Passwords, authentication cookies, and corporate sessions stay in that browser profile. The extension stores source configuration, recent extraction results, source health, and preferences in browser storage.

In this mode, manyCalendars does not receive a copy of your combined calendar. Your calendar provider still sees normal requests when its page opens or refreshes, and your organization's extension and data handling rules still apply.

Optional Cloud Sync and web app access

The personal web calendar cannot display a local browser snapshot without receiving a copy. If you enable Cloud Sync, the extension uploads only the sources you select to the account service over HTTPS.

Busy only is the default. It sends the timing and minimal state needed to draw a busy block. A separate Full details choice can include a title, location, meeting link, and description when those fields are available. Choose Full details only if you are allowed to copy that information into manyCalendars.

Cloud Sync is not end to end encrypted. manyCalendars and its infrastructure provider can technically process synced records. That is the tradeoff for viewing selected calendar copies through the web app on another device.

What Privacy Mode actually does

Privacy Mode changes what manyCalendars renders on screen. In the extension, it replaces event names with “Busy,” substitutes numbered private source labels, closes open detail surfaces, and hides calendar names and event details. The web calendar applies the same idea to titles, source labels, location, organizer, description, attendees, and meeting links.

This is useful for screen sharing, shoulder surfing, or showing a day without exposing client names. It does not erase the underlying event, change the source calendar, or reduce a Cloud Sync record that was already uploaded. Turn Privacy Mode on before sharing your screen, and choose Busy only separately when you want a smaller cloud record.

Calendar Converter processing

The free Calendar Converter reads the file, screenshot, pasted text, or manual entry in the browser. Draft events and the generated ICS file stay on the device.

For a difficult picture, a compatible browser may download an optional reading model from Hugging Face. The picture and recognized text are not included in the model download request. Hugging Face can still receive ordinary request information, such as an IP address and browser details, while serving those model files.

The converter can send a small status event when it is viewed, a conversion starts or ends, an event is added, review is confirmed, or a file is downloaded or shared. That status can include a broad input category, an allowlisted failure category, and a public app version. It is designed not to include the source file, image, extracted text, event names, dates, times, locations, descriptions, ICS contents, email address, or a persistent device identifier.

Retention and deletion, by surface

• Local extension data: clearing extension storage or uninstalling removes the local copy.
• Cloud calendar snapshots: turning off sync for a source removes its server snapshot. Removing the source or deleting the account provides the broader deletion paths described in the Privacy Policy.
• Converter status records: Cloudflare Analytics Engine records may be retained for up to three months under the current service limits.
• Waitlist data: records are kept as needed for access updates, abuse prevention, legal obligations, and deletion or unsubscribe handling. You can request deletion.
• Member account records: account deletion removes calendar snapshots, the feed token, sync counters, and the authentication user. Some transaction or abuse records may need longer retention when required for tax, fraud, disputes, or law.

Uninstalling the extension does not automatically delete a cloud account. Likewise, Privacy Mode does not delete data. Use the control that matches the location shown above.

Four questions to ask before enabling a source

1. Am I allowed to view this calendar in this browser profile?
2. Am I allowed to copy its availability to another tool?
3. Do I need web app access, or can the snapshot stay local?
4. If I enable Cloud Sync, is Busy only enough?

If any answer is unclear, keep that source local or ask the organization that owns the calendar. A browser session proving that you can see data is not the same as a policy saying you may copy it elsewhere.

Product behavior, retention language, and service providers checked August 25, 2026. The Privacy Policy controls if this guide and the policy ever differ.