cal

The "cal" command line tool is a built-in Unix utility for displaying a calendar in the terminal. It provides users with a monthly calendar where they can view the days of the week, dates, and weeks for a specified month or year. By default, it displays the calendar for the current month or year, depending on the chosen options. The "cal" tool can also accept arguments such as the month and year to display a specific calendar. It highlights the current day and can display certain holidays as well. Users can navigate between different months or years using the "cal" command with specific options. The tool can be used in various Unix-like operating systems such as Linux, macOS, FreeBSD, and others. It is a simple yet useful tool for quickly checking dates and planning schedules without leaving the command line interface. The "cal" command can be customized with various options, including date formatting, highlighting weekends, starting the week on a specific day, and more. Overall, the "cal" command line tool provides a quick, accessible, and flexible way to view calendars directly from the terminal.