The R Project SVN – R – Diff – /trunk/src/library/base/man/strptime.Rd



}
\details{
  The \code{format} and \code{as.character} methods and \code{strftime}
  convert objects from the classes \code{"POSIXlt"} and \code{"POSIXct"}
  (not \code{strftime}) to character vectors.
 
  \code{strptime} converts character vectors to class \code{"POSIXlt"}:
  its input \code{x} is first converted by \code{\link{as.character}}.
  Each input string is processed as far as necessary for the format
  specified: any trailing characters are ignored.
 

    \item{\code{\%Y}}{Year with century.  Note that whereas there was no
      zero in the original Gregorian calendar, ISO 8601:2004 defines it
      to be valid (interpreted as 1BC): see
      \url{http://en.wikipedia.org/wiki/0_(year)}.  Note that the standard
      also says that years before 1582 in its calendar should only be used
      with agreement of the parties involved.}
    \item{\code{\%z}}{Signed offset in hours and minutes from UTC, so
      \code{-0800} is 8 hours behind UTC.}
    \item{\code{\%Z}}{(output only.) Time zone as a character
      string (empty if not available).}
  }
  Where leading zeros are shown they will be used on output but are
  optional on input.
 
  Note that when \code{\%z} or \code{\%Z} is used for output with an
  object with an assigned timezone an attempt is made to use the values
  for that timezone --- but it is not guaranteed to succeed.
 
  Also defined in the current standards but less widely implemented
  (e.g. not for output on Windows) are
  \describe{
    \item{\code{\%C}}{Century (00--99): the integer part of the year
      divided by 100.}

\note{
  The default formats follow the rules of the ISO 8601 international
  standard which expresses a day as \code{"2001-02-28"} and a time as
  \code{"14:01:02"} using leading zeroes as here.  The ISO form uses no
  space to separate dates and times.
 
  For \code{strptime} the input string need not specify the date
  completely: it is assumed that unspecified seconds, minutes or hours
  are zero, and an unspecified year, month or day is the current one.
 
  If the timezone specified is invalid on your system, what happens is
  system-specific but it will probably be ignored.
 
  OS facilities will probably not print years before 1 CE (aka 1 AD)
  correctly.

  For links to versions available on-line see (at the time of writing)
  \url{http://dotat.at/tmp/ISO_8601-2004_E.pdf} abd
  \url{http://www.qsl.net/g1smd/isopdf.htm}; for information on the
  current official version, see
  \url{http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html}.
 
  The POSIX 1003.1 standard, which is in some respects stricter than ISO 8601.
}
\seealso{
  \link{DateTimeClasses} for details of the date-time classes;
  \link{locales} to query or set a locale.

The R Project SVN R

(root)/trunk/src/library/base/man/strptime.Rd – Rev 61153 → 61433

Rev 61153		Rev 61433
Line 42...		Line 42...
42	`}`	42	`}`
43	`\details{`	43	`\details{`
44	`The \code{format} and \code{as.character} methods and \code{strftime}`	44	`The \code{format} and \code{as.character} methods and \code{strftime}`
45	`convert objects from the classes \code{"POSIXlt"} and \code{"POSIXct"}`	45	`convert objects from the classes \code{"POSIXlt"} and \code{"POSIXct"}`
46	`(not \code{strftime}) to character vectors.`	46	`(not \code{strftime}) to character vectors.`
47		47
48	`\code{strptime} converts character vectors to class \code{"POSIXlt"}:`	48	`\code{strptime} converts character vectors to class \code{"POSIXlt"}:`
49	`its input \code{x} is first converted by \code{\link{as.character}}.`	49	`its input \code{x} is first converted by \code{\link{as.character}}.`
50	`Each input string is processed as far as necessary for the format`	50	`Each input string is processed as far as necessary for the format`
51	`specified: any trailing characters are ignored.`	51	`specified: any trailing characters are ignored.`
52		52
Line 118...		Line 118...
118	`\item{\code{\%Y}}{Year with century. Note that whereas there was no`	118	`\item{\code{\%Y}}{Year with century. Note that whereas there was no`
119	`zero in the original Gregorian calendar, ISO 8601:2004 defines it`	119	`zero in the original Gregorian calendar, ISO 8601:2004 defines it`
120	`to be valid (interpreted as 1BC): see`	120	`to be valid (interpreted as 1BC): see`
121	`\url{http://en.wikipedia.org/wiki/0_(year)}. Note that the standard`	121	`\url{http://en.wikipedia.org/wiki/0_(year)}. Note that the standard`
122	`also says that years before 1582 in its calendar should only be used`	122	`also says that years before 1582 in its calendar should only be used`
123	`with agreement of the parties involved.}`	123	`with agreement of the parties involved.}`
124	`\item{\code{\%z}}{Signed offset in hours and minutes from UTC, so`	124	`\item{\code{\%z}}{Signed offset in hours and minutes from UTC, so`
125	`\code{-0800} is 8 hours behind UTC.}`	125	`\code{-0800} is 8 hours behind UTC.}`
126	`\item{\code{\%Z}}{(output only.) Time zone as a character`	126	`\item{\code{\%Z}}{(output only.) Time zone as a character`
127	`string (empty if not available).}`	127	`string (empty if not available).}`
128	`}`	128	`}`
129	`Where leading zeros are shown they will be used on output but are`	129	`Where leading zeros are shown they will be used on output but are`
130	`optional on input.`	130	`optional on input.`
131		131
132	`Note that when \code{\%z} or \code{\%Z} is used for output with an`	132	`Note that when \code{\%z} or \code{\%Z} is used for output with an`
133	`object with an assigned timezone an attempt is made to use the values`	133	`object with an assigned timezone an attempt is made to use the values`
134	`for that timezone --- but it is not guaranteed to succeed.`	134	`for that timezone --- but it is not guaranteed to succeed.`
135		135
136	`Also defined in the current standards but less widely implemented`	136	`Also defined in the current standards but less widely implemented`
137	`(e.g. not for output on Windows) are`	137	`(e.g. not for output on Windows) are`
138	`\describe{`	138	`\describe{`
139	`\item{\code{\%C}}{Century (00--99): the integer part of the year`	139	`\item{\code{\%C}}{Century (00--99): the integer part of the year`
140	`divided by 100.}`	140	`divided by 100.}`
Line 206...		Line 206...
206	`\note{`	206	`\note{`
207	`The default formats follow the rules of the ISO 8601 international`	207	`The default formats follow the rules of the ISO 8601 international`
208	`standard which expresses a day as \code{"2001-02-28"} and a time as`	208	`standard which expresses a day as \code{"2001-02-28"} and a time as`
209	`\code{"14:01:02"} using leading zeroes as here. The ISO form uses no`	209	`\code{"14:01:02"} using leading zeroes as here. The ISO form uses no`
210	`space to separate dates and times.`	210	`space to separate dates and times.`
211		211
212	`For \code{strptime} the input string need not specify the date`	212	`For \code{strptime} the input string need not specify the date`
213	`completely: it is assumed that unspecified seconds, minutes or hours`	213	`completely: it is assumed that unspecified seconds, minutes or hours`
214	`are zero, and an unspecified year, month or day is the current one.`	214	`are zero, and an unspecified year, month or day is the current one.`
215		215
216	`If the timezone specified is invalid on your system, what happens is`	216	`If the timezone specified is invalid on your system, what happens is`
217	`system-specific but it will probably be ignored.`	217	`system-specific but it will probably be ignored.`
218		218
219	`OS facilities will probably not print years before 1 CE (aka 1 AD)`	219	`OS facilities will probably not print years before 1 CE (aka 1 AD)`
220	`correctly.`	220	`correctly.`
Line 236...		Line 236...
236	`For links to versions available on-line see (at the time of writing)`	236	`For links to versions available on-line see (at the time of writing)`
237	`\url{http://dotat.at/tmp/ISO_8601-2004_E.pdf} abd`	237	`\url{http://dotat.at/tmp/ISO_8601-2004_E.pdf} abd`
238	`\url{http://www.qsl.net/g1smd/isopdf.htm}; for information on the`	238	`\url{http://www.qsl.net/g1smd/isopdf.htm}; for information on the`
239	`current official version, see`	239	`current official version, see`
240	`\url{http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html}.`	240	`\url{http://www.iso.org/iso/en/prods-services/popstds/datesandtime.html}.`
241		241
242	`The POSIX 1003.1 standard, which is in some respects stricter than ISO 8601.`	242	`The POSIX 1003.1 standard, which is in some respects stricter than ISO 8601.`
243	`}`	243	`}`
244	`\seealso{`	244	`\seealso{`
245	`\link{DateTimeClasses} for details of the date-time classes;`	245	`\link{DateTimeClasses} for details of the date-time classes;`
246	`\link{locales} to query or set a locale.`	246	`\link{locales} to query or set a locale.`