Wyrd is a curses front-end for Remind, a powerful calendar and alarm application. The display features a scrollable time table suitable for visualizing your schedule at a glance. Wyrd integrates with an external editor of your choice to make editing of reminder files more efficient, and provides hotkeys to quickly access the most common Remind options. Other features include extensive configurability, Mutt-like interface design, and minimal resource requirements.
parsical is a Shehensai or parsi calendar application. It's useful for prayers, birthdays, weddings, navjotes, jashans, and other events. It features sunrise calculation based on the computer timezone (as roj begins at sunrise in this calendar), "previous" and "next" month and year buttons, conversion between Gregorian and Shehensai dates, and jumping to the calendar month on a given date or roj.
Address Book Server allows you to share your contacts and calendar events with others connected to your network or over the Internet. Each participant synchronizes their contacts with the server hosted on your own system. Address Book Server supports the full Address Book and iCal schema. The server also provides a friendly Web interface and an iPhone client which let you access your contact details remotely.
DAViCal is a server implementation of the CalDAV protocol for storing calendaring resources (in iCalendar format) on a remote shared server. An increasing number of calendar clients support the maintenance of shared remote calendars through CalDAV including Mozilla Calendar (Sunbird/Lightning), Evolution, Mulberry, Chandler, and various other closed-source products such as Apple's iCal and iPhone. DAViCal supports basic delegation of read/write access among calendar users, multiple users or clients reading and writing the same calendar entries over time, and scheduling of meetings with free/busy time displayed.
Dateutils are a bunch of tools that revolve around fiddling with dates and times in the command line, with a strong focus on use cases that arise when dealing with large amounts of financial data. Their target market is shell scripts that need date calculations or calendar conversions, and as such they are highly pipe-able and modeled after their well-known cousins (e.g. dtest vs. test, or dgrep vs. grep).