cal command means Prints an ASCII calendar of the given month or year. cal command used to see the calendar of a specific month or a whole year.

Syntax
cal [options] [[[day] month] year]
cal [options] [timestamp|monthname]
In man page the describe it
- cal – display a calendar.
- man cal – More details information about cal command.
cal command in Linux with Examples
$ cal
Display last month, this month, and next month.

Display this entire year’s calendar.

Conclusion
cal command is the simple the command in Linux. It is the most popular in use terminal Linux display a calendar.