Jeffrey Hicks has fun with calendars in Powershell:
Some of you may be aware of my PSCalendar module which you can install from the PowerShell Gallery. The module contains commands that you can use to display a console-based calendar. The calendar commands let you specify days to highlight. These might be days with special events or appointments. I typically use the Show-Calendar command as it writes to the host and colorizes output.
This command also has a parameter that lets you specify a position in your console. In other words, you can tell PowerShell where to display the calendar. I recently fixed a bug with the command that was producing less than optimal results. Now, I can use my PowerShell prompt function to display a calendar.
The calendar module and functions are quite helpful, and the calendar prompt merits the Wacky Ideas category.