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Proton Calendar alternatives · Calendar

Alternatives to Proton Calendar with a one-time purchase

The Proton Calendar listing shows no one-time purchase. 11 of the 75 other calendar and scheduling apps in this directory can be bought with a one-time purchase.

Proton Calendar has a free plan. Paid plans start at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly. 8 of them are free or have a free plan.

11 tools · Listings checked up to Oct 9, 2026 · Where the facts come from

How each one differs from Proton Calendar

  1. BusyCal

    Customizable calendar and task app for Mac and iPhone

    • BusyCal starts at $49.99 one-time for Mac, or $39.99 per year on the Mac App Store; iOS app $9.99. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists Windows, Linux and Android apps.
    • BusyCal can be bought with a one-time purchase.
    BusyCal pricing and details

  2. TidyCal

    Booking pages with paid bookings and one-time lifetime plans

    • TidyCal starts at $29 one-time (Individual Lifetime), or Pro at $8.25 per month billed annually ($99). Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists macOS, Windows, Linux, iOS and Android apps.
    • TidyCal can be bought with a one-time purchase.
    • Proton Calendar is open source and end-to-end encrypted, according to its own site.
    TidyCal pricing and details

  3. Calendar 366

    Calendar and task app for iPhone, iPad, Apple Watch and Mac

    • Calendar 366 starts at $19.99 per year for Pro on the App Store. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists Windows, Linux and Android apps.
    • Calendar 366 can be bought with a one-time purchase.
    Calendar 366 pricing and details

  4. Dato

    Mac menu bar calendar with world clocks and meeting alerts

    • Dato starts at $18 one-time purchase on the Mac App Store. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Proton Calendar has a free plan. Dato does not, though it has a free trial.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists Windows, Linux, iOS and Android apps.
    Dato pricing and details

  5. One Calendar

    One view of all your calendars on Android, Apple and Windows

    • One Calendar starts at $5.99 one-time per platform (App Store or Google Play). Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists a Linux app.
    • One Calendar can be bought with a one-time purchase.
    One Calendar pricing and details

  6. DigiCal

    Android calendar with seven views, widgets and weather forecasts

    • DigiCal starts at $5.49 one-time for DigiCal+ on Google Play. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists macOS, Windows, Linux and iOS apps.
    • DigiCal can be bought with a one-time purchase.
    DigiCal pricing and details

  7. aCalendar

    Android calendar with widgets, tasks and one-time upgrades

    • aCalendar starts at $2.49 to $11.99 per one-time in-app upgrade; aCalendar+ is $11.99. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists macOS, Windows, Linux and iOS apps.
    • aCalendar can be bought with a one-time purchase.
    aCalendar pricing and details

  8. CalenGoo

    Highly configurable calendar and task app sold as a one-time purchase

    • CalenGoo starts at $5.99 one-time for Android; $6.99 for iOS; $49.99 for the desktop app. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Proton Calendar has a free plan. CalenGoo does not, though it has a free trial.
    • Only Proton Calendar lists a web app.
    • CalenGoo can be bought with a one-time purchase.
    CalenGoo pricing and details

  9. Rainlendar

    Skinnable desktop calendar for Windows, Mac and Linux

    • Rainlendar starts at €9.95 one-time for a lifetime Rainlendar Pro license. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists iOS and Android apps.
    • Rainlendar can be bought with a one-time purchase.
    Rainlendar pricing and details

  10. In Your Face

    Full-screen meeting reminders for Mac, Windows, iPhone and iPad

    • In Your Face starts at $3.99 per month, or $24.99 per year. Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Proton Calendar has a free plan. In Your Face does not, though it has a free trial.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists Linux and Android apps.
    In Your Face pricing and details

  11. Supershift

    Shift work calendar app with rotations, reports and sharing

    • Supershift starts at $3.99 per month, or $9.99 per year (Supershift Pro). Proton Calendar starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly.
    • Only Proton Calendar lists a web app.
    • Only Proton Calendar lists macOS, Windows and Linux apps.
    • Supershift can be bought with a one-time purchase.
    Supershift pricing and details

Common questions

Is there an alternative to Proton Calendar that you buy once?

Yes. BusyCal, TidyCal, Calendar 366, Dato, One Calendar, DigiCal, aCalendar, CalenGoo and 3 more can be bought with a one-time purchase.

Can you buy Proton Calendar once instead of subscribing?

The Proton Calendar listing shows no one-time purchase. The listing was checked on Oct 5, 2026 against the pages it cites.

Which of these calendar and scheduling apps are free?

BusyCal, TidyCal, Calendar 366, One Calendar, DigiCal, aCalendar, Rainlendar and Supershift are free or have a free plan.

When was this checked?

Each listing shows its own date. On this page they run from Oct 5, 2026 to Oct 9, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Proton Calendar: the alternatives its listing names first, then the tools that share the most features with it.