Rewrote length method.

src/@dates/length.m

-function n = length(A)
+function n = length(o)
 
 % Returns the number of elements in a dates object.
-
-% Copyright (C) 2013 Dynare Team
 %
-% This file is part of Dynare.
+% INPUTS 
+% - o [dates]
+%
+% OUTPUTS 
+% - n [integer] Number of elements in o.
+
+% Copyright (C) 2013-2014 Dynare Team
 %
-% Dynare is free software: you can redistribute it and/or modify
+% This code 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.
 %
-% Dynare is distributed in the hope that it will be useful,
+% Dynare dates submodule 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.
@@ -19,4 +23,25 @@ function n = length(A)
 % You should have received a copy of the GNU General Public License
 % along with Dynare.  If not, see <http://www.gnu.org/licenses/>.
 
-n = A.ndat;
\ No newline at end of file
+n = o.ndat;
+
+%@test:1
+%$ d = dates('1938Q1');
+%$ % Test if this object is empty
+%$ t(1) = isequal(d.length(),1);
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ d = dates();
+%$ % Test if this object is empty
+%$ t(1) = isequal(d.length(),0);
+%$ T = all(t);
+%@eof:2
+
+%@test:3
+%$ d = dates('1938Q1')+dates('1938Q2')+dates('1938Q3');
+%$ % Test if this object is empty
+%$ t(1) = isequal(d.length(),3);
+%$ T = all(t);
+%@eof:3
\ No newline at end of file