Using cal command of Ubuntu When I want to see a calendar on Ubuntu, I just command like this:

$ cal -3


Then, it displays prev/current/next month output.

But, the cal command of OSX is a bit different from Ubuntu's, and there's no -3 option.

If I see the history section of man page, OSX's looks like this


  A cal command appeared in Version 5 AT&amp;T UNIX. The ncal command appeared in FreeBSD 2.2.6.


And, the history section of Ubuntu's man page says


  A cal command appeared in Version 6 AT&amp;T UNIX. Several much more elaborate versions of this program exist, with support for colors, holidays, birthdays, reminders and appointments, etc. For example, try the cal from http://home.sprynet.com/~cbagwell/projects.html or GNU gcal.


Can I use Ubuntu's cal command on OSX?
I've been searching for cal -3 functionality on Mac as well.

From your quote, there's an alternative, GNU gcal, which is radically different from cal command. There's a tutorial that's easy to follow as well.

So I settled with it. You can type gcal . for cal -3 equivalent.