diff --git a/doc/dynare.texi b/doc/dynare.texi
index c192c4e35..01f1ddc93 100644
--- a/doc/dynare.texi
+++ b/doc/dynare.texi
@@ -8920,6 +8920,27 @@ C = <dates: 1951Q1, 1951Q2, 1951Q3, 1951Q4>
 
 @sp 1
 
+@deftypefn{dates} {@var{C} =} setdiff(@var{A}, @var{B})
+
+Overloads the Matlab/Octave @code{setdiff} function. All the input arguments must be @dates objects. The returned argument is a @dates object all dates present in @var{A} but not in @var{B}. If @var{A} and @var{B} are disjoint @dates objects, the function returns @var{A}. Returned dates in @dates object @var{C} are sorted by increasing order.
+
+@examplehead
+@example
+>> A = dates('1950Q1'):dates('1969Q4') ;
+>> B = dates('1960Q1'):dates('1969Q4') ;
+>> C = dates('1970Q1'):dates('1979Q4') ;
+>> d1 = setdiff(d1,d2);
+>> d2 = setdiff(d1,d3);
+d1 = <dates: 1950Q1, 1950Q2,  ..., 1959Q3, 1959Q4>
+d2 = <dates: 1950Q1, 1950Q2,  ..., 1969Q3, 1969Q4>
+@end example
+
+@end deftypefn
+
+
+@sp 1
+
+
 @deftypefn{dates} {@var{B} =} isempty (@var{A})
 
 Overloads the Matlab/Octave isempty function for @dates object.
diff --git a/matlab/@dates/setdiff.m b/matlab/@dates/setdiff.m
new file mode 100644
index 000000000..fb0228c0e
--- /dev/null
+++ b/matlab/@dates/setdiff.m
@@ -0,0 +1,88 @@
+function C = setdiff(A,B) % --*-- Unitary tests --*--
+
+%@info:
+%! @deftypefn {Function File} {@var{C} =} setdiff (@var{A},@var{B})
+%! @anchor{@dates/intersect}
+%! @sp 1
+%! C of B and A.
+%! if A and B are not disjoints.
+%! @sp 2
+%! @strong{Inputs}
+%! @sp 1
+%! @table @ @var
+%! @item A
+%! @ref{dates} object.
+%! @item B
+%! @ref{dates} object.
+%! @end table
+%! @sp 2
+%! @strong{Outputs}
+%! @sp 1
+%! @table @ @var
+%! @item C
+%! @ref{dates} object.
+%! @end table
+%! @end deftypefn
+%@eod:
+
+% Copyright (C) 2013 Dynare Team
+%
+% This file is part of Dynare.
+%
+% Dynare 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,
+% 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 Dynare.  If not, see <http://www.gnu.org/licenses/>.
+
+if ~isa(A,'dates') || ~isa(B,'dates')
+    error(['dates::plus: Input arguments ''' inputname(1) ''' and ''' inputname(2) ''' must be dates objects!'])
+end
+
+if eq(A,B)
+    C = A;
+    return
+end
+
+if ~isequal(A.freq,B.freq)
+    C = dates();
+    return
+end
+
+if isoctave || matlab_ver_less_than('8.1.0')
+    time = setdiff(A.time,B.time,'rows');
+else
+    time = setdiff(A.time,B.time,'rows','legacy');
+end
+
+C = dates();
+if isempty(time)
+    return
+end
+
+C.freq = A.freq;
+C.time = time;
+C.ndat = rows(time); 
+
+%@test:1
+%$ % Define some dates objects
+%$ d1 = dates('1950Q1'):dates('1969Q4') ;
+%$ d2 = dates('1960Q1'):dates('1969Q4') ;
+%$ d3 = dates('1970Q1'):dates('1979Q4') ;
+%$
+%$ % Call the tested routine.
+%$ c1 = intersect(d1,d2);
+%$ c2 = intersect(d1,d3);
+%$
+%$ % Check the results.
+%$ t(1) = dyn_assert(isequal(c1,d2),1);
+%$ t(2) = dyn_assert(isempty(c2),1);
+%$ T = all(t);
+%@eof:1
\ No newline at end of file
diff --git a/matlab/basic_plan.m b/matlab/basic_plan.m
index a2e11477f..22ef0cb85 100644
--- a/matlab/basic_plan.m
+++ b/matlab/basic_plan.m
@@ -42,24 +42,28 @@ function plan = basic_plan(plan, exogenous, expectation_type, date, value)
   sdate = length(date);
   if sdate > 1
       if date(1) < plan.date(1) || date(end) > plan.date(end)
-          error(['in basic_plan the forth argument (date='  date ') must lay inside the plan.date ' plan.date]);
+          error(['in basic_plan the fourth argument (date='  date ') must lay inside the plan.date ' plan.date]);
       end
   else
       if date < plan.date(1) || date > plan.date(end)
-          error(['in basic_plan the forth argument (date='  date ') must lay iside the plan.date ' plan.date]);
+          error(['in basic_plan the fourth argument (date='  date ') must lay iside the plan.date ' plan.date]);
       end
   end
+  if length(date) ~= length(value)
+      error(['in basic_plan the number of dates (' int2str(length(date)) ') is not equal to the numbers of shock (' int2str(length(value)) ') for exogenous variable ' exogenous]);
+  end
   if ~isempty(plan.options_cond_fcst_.controlled_varexo)
       common_var = find(ix == plan.options_cond_fcst_.controlled_varexo);
       if ~isempty(common_var)
           common_date = intersect(date, plan.constrained_date_{common_var});
           if ~isempty(common_date)
+              date = setdiff(date, common_date);
               if common_date.length > 1
                   the_dates = [cell2mat(strings(common_date(1))) ':' cell2mat(strings(common_date(end)))];
               else
                   the_dates = cell2mat(strings(common_date));
               end
-              error(['Impossible case: ' plan.exo_names{plan.options_cond_fcst_.controlled_varexo(common_var)} ' is used both as a shock and as an endogenous variable to control the path of ' plan.endo_names{plan.constrained_vars_(common_var)} ' at the dates ' the_dates]);
+              warning(['Impossible case: ' plan.exo_names{plan.options_cond_fcst_.controlled_varexo(common_var)} ' is used both as a shock and as an endogenous variable to control the path of ' plan.endo_names{plan.constrained_vars_(common_var)} ' at the dates ' the_dates]);
           end
       end
   end