\HeaderA{seq.Date}{Generate Regular Sequences of Dates}{seq.Date}
\keyword{manip}{seq.Date}
\keyword{chron}{seq.Date}
\begin{Description}\relax
The method for \code{\LinkA{seq}{seq}} for date-time classes.
\end{Description}
\begin{Usage}
\begin{verbatim}
## S3 method for class 'Date':
seq(from, to, by, length.out = NULL, along.with = NULL, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{from}] starting date. Required
\item[\code{to}] end date. Optional.
\item[\code{by}] increment of the sequence. Optional. See Details.
\item[\code{length.out}] integer, optional. desired length of the sequence.
\item[\code{along.with}] take the length from the length of this argument.
\item[\code{...}] arguments passed to or from other methods.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{by} can be specified in several ways.
\Itemize{
\item A number, taken to be in days.
\item A object of class \code{\LinkA{difftime}{difftime}}
\item A character string, containing one of \code{"day"},
\code{"week"}, \code{"month"} or \code{"year"}.  This can optionally be
preceded by a (positive or negative) integer and a space,
or followed by \code{"s"}.

See \code{\LinkA{seq.POSIXt}{seq.POSIXt}} for the details of \code{"month"}.
}
\end{Details}
\begin{Value}
A vector of class \code{"Date"}.
\end{Value}
\begin{SeeAlso}\relax
\code{\LinkA{Date}{Date}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
## first days of years
seq(as.Date("1910/1/1"), as.Date("1999/1/1"), "years")
## by month
seq(as.Date("2000/1/1"), by="month", length=12)
## quarters
seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by="3 months")

## find all 7th of the month between two dates, the last being a 7th.
st <- as.Date("1998-12-17")
en <- as.Date("2000-1-7")
ll <- seq.Date(en, st, by="-1 month")
rev(ll[ll > st & ll < en])
\end{ExampleCode}
\end{Examples}

