diff --git a/matlab/@dates/double.m b/matlab/@dates/double.m
new file mode 100644
index 000000000..6c73f8e7d
--- /dev/null
+++ b/matlab/@dates/double.m
@@ -0,0 +1,81 @@
+function [B, C]  = double(A)
+
+% Returns a vector of doubles with the fractional part corresponding
+% to the subperiod. Used for plots and to store dates in a matrix.
+%
+% INPUTS 
+%  o A     dates object.
+%
+% OUTPUTS  
+%  o B     A.ndat*1 vector of doubles.
+%  o C     integer scalar, the frequency (1, 4, 12 or 52).
+%
+% REMARKS 
+%  Obviously the frequency is lost during the conversion.
+    
+% 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/>.
+
+B = A.time(:,1)+(A.time(:,2)-1)/A.freq;
+if nargout>1
+    C = A.freq;
+end
+
+%@test:1
+%$ % Define a dates object
+%$ qq = dates('Q');
+%$ B = qq(1950,1):qq(1951,1);
+%$
+%$ % Call the tested routine.
+%$ try
+%$     C = double(B);
+%$     t(1) = 1;
+%$ catch
+%$     t(1) = 0;
+%$ end
+%$
+%$ % Define expected results.
+%$ E = [ones(4,1)*1950; 1951];
+%$ E = E + [(transpose(1:4)-1)/4; 0];
+%$ if t(1)
+%$     t(2) = dyn_assert(isequal(C,E),1);
+%$ end
+%$ T = all(t);
+%@eof:1
+
+%@test:2
+%$ % Define a dates object
+%$ qq = dates('Q');
+%$
+%$ % Call the tested routine.
+%$ try
+%$     C = NaN(2,1);
+%$     C(1) = double(qq(1950,1));
+%$     C(2) = double(qq(1950,2));
+%$     t(1) = 1;
+%$ catch
+%$     t(1) = 0;
+%$ end
+%$
+%$ % Define expected results.
+%$ E = ones(2,1)*1950;
+%$ E = E + [0; .25];
+%$ if t(1)
+%$     t(2) = dyn_assert(isequal(C,E),1);
+%$ end
+%$ T = all(t);
+%@eof:2
\ No newline at end of file
diff --git a/matlab/@dates/dynDates2decimal.m b/matlab/@dates/dynDates2decimal.m
deleted file mode 100644
index 4a50881ef..000000000
--- a/matlab/@dates/dynDates2decimal.m
+++ /dev/null
@@ -1,23 +0,0 @@
-function y = dates2decimal(dd)
-% function y = dates2decimal(dd)
-%     returns a vector of doubles with the fractional part corresponding
-%     to the subperiod. Mostly used for plots.
-    
-% 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/>.
-
-    y = dd.time(:,1)+(dd.time(:,2)-1)/dd.freq;
\ No newline at end of file