Rainlendar!

Fantastical is a flexible calendar with natural language event creation, a beautiful calendar and event list, support for CalDAV (including Google Calendar delegates) automatic alarms, and instant searching.

An offline calendar without any other calendar integration. You can easily create recurring events and setup reminders, it can also display week numbers.

Take control of your schedule and get reminded wherever and however you want. Instantly access your appointments, tasks, and notes with a simple glance at a transparent calendar that sits right on your Windows desktop. Share calendars and reminders in your home, office, or online. Automatically synchronize with Google Calendar and Outlook. Print calendars using a wide variety of layouts and styles. You can do all these things and much more with VueMinder Calendar.

This application is a software calendar with appointments notes, tasks, alarms and contacts that provides seamless integration and interactivity with the desktop background. You can organize your data in layers and share them with other people on a local area network.

Holiline Reminder is both an event reminder and a calendar. Holiline’s aim is to ensure that you do not forget about a friend’s birthday, an important holiday, or another significant event. By default, it takes over the taskbar to remind you about important events that are coming up.

Orage is a new modern calendar application for the Xfce Desktop Environment. Orage has been designed from the start to be quick and easy-to-use. Its user interface is clean and intuitive, and does not include any confusing or useless options. Orage is fast and responsive and uses minimal system resources. Orage has been translated into several (currently about 30) languages.

CalenGoo gives you a fast and easy way to access and change your Google Calendar (or Google Apps Calendar) with your Android device. It can either work with the built-in calendar or it can sync directly with Google.

This program helps you organizing your dates and tasks and reminds you of upcoming events.

GMinder is a reminder program that waits in your system tray and alerts you when you have an upcoming Google Calendar event.

30 Boxes is an online calendering tool.

BEAUTIFULLY DESIGNEDDigiCal’s diary planner and organizer provides a clear and beautiful overview for your events and appointments.• Conveniently switch between 7 calendar views (day, week, week agenda, month calendar, text month, year and list view in portrait and landscape mode).• The slick dark theme allows for better visibility in low-light settings and night mode.• Event keyword image matching available in all 27 languages!• 6 highly customizable widgets with different theme styles and views: (FREE: list, day, day list, day grid widgets; PREMIUM: 2 extra widgets –text month and month calendar widget)• Intuitive navigation between days, weeks and months with zoomable day and week view. »

KOrganizer is the calendar and scheduling component of Kontact, the integrated personal information manager from KDE.