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

Manage your schedule

Quản lý thư tín, lịch biểu và các liên lạc

A simple kanban-styled planner

A simple graphical tool to purge old events from CalDAV calendars

An amazing calendar widget

Personal organizer

A time related task manager

A Persian/Jalali/Farsi calendar