\Header{hist.POSIXt}{Histogram of a Date-Time Object}
\keyword{chron}{hist.POSIXt}
\keyword{dplot}{hist.POSIXt}
\keyword{hplot}{hist.POSIXt}
\begin{Description}\relax
Method for \code{\Link{hist}} applied to date-time objects.\end{Description}
\begin{Usage}
\begin{verbatim}
hist(x, breaks, ..., plot = TRUE, freq = FALSE,
     start.on.monday = TRUE, format)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] an object inheriting from class \code{"POSIXt"}.
\item[\code{breaks}] a vector of cut points \emph{or} number giving the number of
intervals which \code{x} is to be cut into \emph{or} an
interval specification, one of \code{"secs"}, \code{"mins"},
\code{"hours"}, \code{"days"}, \code{"weeks"}, \code{"months"}
or \code{"years"}.

\item[\code{...}] graphical parameters.
\item[\code{plot}] logical.  If \code{TRUE} (default), a histogram is
plotted, otherwise a list of breaks and counts is returned.
\item[\code{freq}] logical; if \code{TRUE}, the
histogram graphic is a representation of frequencies, i.e,
the \code{counts} component of the result; if \code{FALSE},
\emph{relative} frequencies (``probabilities'') are plotted.
\item[\code{start.on.monday}] logical. If \code{breaks = "weeks"}, should the
week start on Mondays or Sundays?
\item[\code{format}] for the x-axis labels. See \code{\Link{strptime}}.
\end{ldescription}
\end{Arguments}
\begin{Value}
An object of class \code{"histogram"}: see \code{\Link{hist}}.\end{Value}
\begin{SeeAlso}\relax
\code{\Link{seq.POSIXt}}, \code{\Link{axis.POSIXct}}, \code{\Link{hist}}\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
hist(.leap.seconds, "years", freq = TRUE)
hist(.leap.seconds,
     seq(ISOdate(1970, 1, 10), ISOdate(2002, 1, 1), "5 years"))

## 100 random dates in a 10-week period
random.dates <- ISOdate(2001, 1, 1) + 70*86400*runif(100)
hist(random.dates, "weeks", format = "%d %b")
\end{ExampleCode}
\end{Examples}

