Alternatives to Proton Calendar

Lark

Lark's Starter plan is described for small teams with simple communication needs.

Teamup suits businesses and teams coordinating schedules, resources or operations, from room bookings to field-crew job schedules.

Calendar.com

It suits individuals who want free calendar and scheduling tools, as well as teams needing shared availability, booking workflows, or analytics.

TimeFinder may suit individuals who plan their day by assigning tasks to time slots and want templates or rollover for recurring routines.

Amie

Amie suits people who want meeting notes and action items linked to calendar planning and to-dos.

Tuta Calendar

It suits people and organizations seeking privacy-focused calendar use, including businesses, journalists, activists, and personal users.

Fastmail Calendar

It suits individuals, families and businesses that want calendar sharing alongside Fastmail email.

Reclaim AI

Reclaim AI suits individuals, teams, and companies that want scheduling around work and life priorities using Google Calendar or Outlook Calendar.

Tilly suits people whose time is split across calendar accounts and who want tasks visible alongside their schedule.

Cozi

Cozi suits households coordinating shared calendars, errands, chores, and meal plans across web and mobile.

TimeTree

TimeTree suits groups that want shared calendars with comments, photos, and filters across multiple calendars.

Tweek

Tweek suits people who want calendar-based task planning with shared calendars and mobile apps.

Ellie Planner

Ellie suits people who want a daily planner centered on Brain Dump and Kanban-based planning, or who want a native iOS app.

eM Client

eM Client suits individuals and teams who want email alongside calendars, tasks, contacts, notes, and chat across desktop and mobile platforms.

FlowSavvy

FlowSavvy is aimed at busy individuals who want auto-scheduling without team or enterprise features.