--- /dev/null
+## Copyright (C) 2004-2012 Paul Kienzle
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{c} =} calendar ()
+## @deftypefnx {Function File} {@var{c} =} calendar (@var{d})
+## @deftypefnx {Function File} {@var{c} =} calendar (@var{y}, @var{m})
+## @deftypefnx {Function File} {} calendar (@dots{})
+## Return the current monthly calendar in a 6x7 matrix.
+##
+## If @var{d} is specified, return the calendar for the month containing
+## the date @var{d}, which must be a serial date number or a date string.
+##
+## If @var{y} and @var{m} are specified, return the calendar for year @var{y}
+## and month @var{m}.
+##
+## If no output arguments are specified, print the calendar on the screen
+## instead of returning a matrix.
+## @seealso{datenum, datestr}
+## @end deftypefn
+
+## Author: pkienzle <pkienzle@users.sf.net>
+## Created: 25 July 2004
+## Adapted-By: William Poetra Yoga Hadisoeseno <williampoetra@gmail.com>
+
+function varargout = calendar (varargin)
+
+ switch (nargin)
+ case 0
+ v = clock ();
+ y = v(1);
+ m = v(2);
+ d = v(3);
+ case 1
+ v = datevec (varargin{1});
+ y = v(1);
+ m = v(2);
+ d = v(3);
+ case 2
+ y = varargin{1};
+ m = varargin{2};
+ d = [];
+ otherwise
+ print_usage ();
+ endswitch
+
+ c = zeros (7, 6);
+ dayone = datenum (y, m, 1);
+ ndays = eomday (y, m);
+ c(weekday (dayone) - 1 + [1:ndays]) = 1:ndays;
+
+ if (nargout > 0)
+ varargout{1} = c';
+ else
+ ## Layout the calendar days, 6 columns per day, 7 days per row.
+ str = sprintf (" %2d %2d %2d %2d %2d %2d %2d\n", c);
+
+ ## Print an asterisk before the specified date
+ if (! isempty (d))
+ pos = weekday (dayone) + d - 1;
+ idx = 6*pos + fix (pos / 7.1) - ifelse (d < 10, 1, 2);
+ str(idx) = "*";
+ endif
+
+ ## Display the calendar.
+ s.year = y - 1900;
+ s.mon = m - 1;
+ puts (strftime (" %b %Y\n", s));
+ puts (" S M Tu W Th F S\n");
+ puts (str);
+ endif
+
+endfunction
+
+
+## demos
+%!demo
+%! ## Calendar for current month
+%! calendar ()
+%!demo
+%! calendar (1957, 10)
+
+## tests
+%!assert ((calendar(2000,2))'(2:31), [0:29])
+%!assert ((calendar(1957,10))'(2:33), [0:31])
+
+%% Test input validation
+%!error calendar (1,2,3)
+