

    \filetitle{datdiff}{Number of periods between two dates with check for date frequency}{dates/datdiff}

	\paragraph{Syntax}

\begin{verbatim}
D = datdiff(D1,D2)
\end{verbatim}

\paragraph{Input arguments}

\begin{itemize}
\itemsep1pt\parskip0pt\parsep0pt
\item
  \texttt{D1}, \texttt{D2} {[} numeric {]} - IRIS dates of vectors of
  IRIS dates.
\end{itemize}

\paragraph{Output arguments}

\begin{itemize}
\itemsep1pt\parskip0pt\parsep0pt
\item
  \texttt{D} {[} numeric {]} - Number of periods between \texttt{D1} and
  \texttt{D2}, positive for \texttt{D1} greater than \texttt{D2},
  negative for \texttt{D1} smaller than \texttt{D2}, or NaN for dates of
  different frequencies.
\end{itemize}

\paragraph{Description}

\paragraph{Example}

\begin{verbatim}
d1 = mm(2010,12);
d2 = mm(2011,12);

datdiff(d1,d2)
ans =
   -12

datdiff(d2,d1)
ans =
    12

d3 = yy(2011);
datdiff(d1,d3)
ans =
   NaN
\end{verbatim}


