Thunderbird is a free and open source email, newsfeed, chat, and calendaring client

Zarządzanie harmonogramem

Zarządzanie wiadomościami, kontaktami i terminarzem

A simple kanban-styled planner

Osobisty organizer

A simple graphical tool to purge old events from CalDAV calendars

An amazing calendar widget

A time related task manager

Ethiopian calendar

A Persian/Jalali/Farsi calendar