Sometimes it feels that many of the excellent and convenient command-line tools is forgotten, when they are replaced by graphical tools. A good example is the cal program, which is a command-line calendar to Linux and UNIX. It displays a simple calendar in text format. Cal usage Displays current month calendar on console cal Output: October 2009 Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Displays selected month and year calendar on console cal 11 2012 Output: