---
title: VPN供应商
icon: material/calendar
description: Calendars contain some of your most sensitive data; use products that implement encryption at rest.
cover: calendar.webp
---

<small>Protects against the following threat(s):</small>

- [:material-bug-outline: 被动攻击](basics/common-threats.md#security-and-privacy ""){.pg-orange}
- [:material-server-network: 服务提供商](basics/common-threats.md#privacy-from-service-providers ""){.pg-teal}

**Calendars** contain some of your most sensitive data; use products that implement end-to-end encryption at rest to prevent a provider from reading them.

## Tuta

<div class="admonition recommendation" markdown>

![Tuta logo](assets/img/email/tuta.svg#only-light){ align=right }
![Tuta logo](assets/img/email/tuta-dark.svg#only-dark){ align=right }

**Tuta** offers a free and encrypted calendar across their supported platforms. Features include automatic E2EE of all data, sharing features, import/export functionality, multifactor authentication, and [more](https://tuta.com/calendar-app-comparison).

Multiple calendars and extended sharing functionality are limited to paid subscribers.

[:octicons-home-16: Homepage](https://tuta.com/calendar){ .md-button .md-button--primary }
[:octicons-eye-16:](https://tuta.com/privacy){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://tuta.com/support){ .card-link title="Documentation" }
[:octicons-code-16:](https://github.com/tutao/tutanota){ .card-link title="Source Code" }
[:octicons-heart-16:](https://tuta.com/community#donate){ .card-link title="Contribute" }

<details class="downloads" markdown>
<summary>Downloads</summary>

- [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=de.tutao.calendar)
- [:simple-appstore: App Store](https://apps.apple.com/app/id6657977811)
- [:simple-github: GitHub](https://github.com/tutao/tutanota/releases?q=Calendar)
- [:fontawesome-brands-windows: Windows](https://tuta.com/blog/desktop-clients)
- [:simple-apple: macOS](https://tuta.com/blog/desktop-clients)
- [:simple-linux: Linux](https://tuta.com/blog/desktop-clients)
- [:simple-flathub: Flathub](https://flathub.org/apps/com.tutanota.Tutanota)
- [:octicons-browser-16: Web](https://app.tuta.com)

</details>

</div>

## Proton Calendar（Proton 日历）

<div class="admonition recommendation" markdown>

![Proton](assets/img/calendar/proton-calendar.svg){ align=right }

**Proton Calendar** is an encrypted calendar service available to Proton members via its web or mobile clients. Features include automatic E2EE of all data, sharing features, import/export functionality, and [more](https://proton.me/support/proton-calendar-guide).

Those on the free tier have access to 3 calendars, whereas paid subscribers can create up to 25 calendars. 扩展的分享功能也仅限于付费用户。

[:octicons-home-16: Homepage](https://proton.me/calendar){ .md-button .md-button--primary }
[:octicons-eye-16:](https://proton.me/calendar/privacy-policy){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://proton.me/support/calendar){ .card-link title="Documentation" }
[:octicons-code-16:](https://github.com/orgs/ProtonMail/repositories?q=calendar){ .card-link title="Source Code" }

<details class="downloads" markdown>
<summary>Downloads</summary>

- [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=me.proton.android.calendar)
- [:simple-appstore: App Store](https://apps.apple.com/app/id1514709943)
- [:octicons-browser-16: Web](https://calendar.proton.me)

</details>

</div>

In 2021, Securitum [audited](https://proton.me/community/open-source#:~:text=Proton%20Calendar) Proton Calendar's web client and provided a [letter of attestation](https://res.cloudinary.com/dbulfrlrz/images/v1714639870/wp-pme/letter-of-attestation-proton-calendar-20211109_3138998f9b/letter-of-attestation-proton-calendar-20211109_3138998f9b.pdf) for the Android app.

## Criteria

**Please note we are not affiliated with any of the projects we recommend.** In addition to [our standard criteria](about/criteria.md), we have developed a clear set of requirements to allow us to provide objective recommendations. We suggest you familiarize yourself with this list before choosing to use a project, and conduct your own research to ensure it's the right choice for you.

### Minimum Qualifications

- 必须与E2EE同步并存储信息，以确保数据对服务提供者不可见。

### Best-Case

Our best-case criteria represents what we would like to see from the perfect project in this category. Our recommendations may not include any or all of this functionality, but those which do may rank higher than others on this page.

- 如果适用的话，应该与本地操作系统的日历和联系人管理应用程序集成。
