Sorry - messed up example: corrected here... d <- "7/27/77" strptime(d, format="%m/%d/%y") # "1977-07-27 EDT" x <- strptime(d, format="%m/%d/%y") strftime(x, format="%m/%d/%Y") # "07/27/1977" On Feb 3, 2016, at 1:29 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote:> It seems your autocorrect is playing tricks on you but if I understand you correctly you have a two digit year and want to convert that to a four digit year? That's not uniquely possible of course; by convention, as the documentation to strptime() says: > > On input, values 00 to 68 are prefixed by 20 and 69 to 99 by 19 ? that > is the behaviour specified by the 2004 and 2008 POSIX standards... > > If this is correct for you, you need to convert the string to a time object and the time object back to string. The format specifier %Y prints four-digit years: > > > d <- "7/27/59" > strptime(d, format="%m/%d/%y") # "2059-07-27 EDT" > x <- strptime(d, format="%m/%d/%y") > > strftime(x, format="%m/%d/%Y") # "07/27/1977" > > > > B. > > > > > > > > On Feb 3, 2016, at 11:03 AM, carol white via R-help <r-help at r-project.org> wrote: > >> Hi,might be trivial but how to determine the year of a date which is in the %m/%d/%y format and those whose year is century should be modified to ISO so that all date will have with year in ISO? >> Regards, >> Carol >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
yes, some of them are like 09/01/15 and some others are 09/01/2015 and all of
them range between 2015 and 2016. The goal was to convert 09/01/15 to
09/01/2015. I don't know if the fact that they range between 2015 and 2016
make the task easier.
Best wishes
Carol
On Wednesday, February 3, 2016 7:34 PM, Boris Steipe <boris.steipe at
utoronto.ca> wrote:
Sorry - messed up example: corrected here...
d <- "7/27/77"
strptime(d, format="%m/%d/%y")? #? "1977-07-27 EDT"
x <- strptime(d, format="%m/%d/%y")
strftime(x, format="%m/%d/%Y")? # "07/27/1977"
On Feb 3, 2016, at 1:29 PM, Boris Steipe <boris.steipe at utoronto.ca>
wrote:
> It seems your autocorrect is playing tricks on you but if I understand you
correctly you have a two digit year and want to convert that to a four digit
year? That's not uniquely possible of course; by convention, as the
documentation to strptime() says:
>
>? On input, values 00 to 68 are prefixed by 20 and 69 to 99 by 19 ? that
>? is the behaviour specified by the 2004 and 2008 POSIX standards...
>
> If this is correct for you, you need to convert the string to a time object
and the time object back to string. The format specifier %Y prints four-digit
years:
>
>
> d <- "7/27/59"
> strptime(d, format="%m/%d/%y")? # "2059-07-27 EDT"
> x <- strptime(d, format="%m/%d/%y")
>
> strftime(x, format="%m/%d/%Y")? # "07/27/1977"
>
>
>
> B.
>
>
>
>
>
>
>
> On Feb 3, 2016, at 11:03 AM, carol white via R-help <r-help at
r-project.org> wrote:
>
>> Hi,might be trivial but how to determine the year of a date which is in
the %m/%d/%y format and those whose year is century should be modified to ISO so
that all date will have with year in ISO?
>> Regards,
>> Carol
>>
>> ??? [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
As the documentation says, that's exactly what the expansion will do by default. B. On Feb 3, 2016, at 2:31 PM, carol white <wht_crl at yahoo.com> wrote:> yes, some of them are like 09/01/15 and some others are 09/01/2015 and all of them range between 2015 and 2016. The goal was to convert 09/01/15 to 09/01/2015. I don't know if the fact that they range between 2015 and 2016 make the task easier. > > Best wishes > Carol > > > On Wednesday, February 3, 2016 7:34 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote: > > > Sorry - messed up example: corrected here... > > d <- "7/27/77" > strptime(d, format="%m/%d/%y") # "1977-07-27 EDT" > x <- strptime(d, format="%m/%d/%y") > > strftime(x, format="%m/%d/%Y") # "07/27/1977" > > > On Feb 3, 2016, at 1:29 PM, Boris Steipe <boris.steipe at utoronto.ca> wrote: > > > It seems your autocorrect is playing tricks on you but if I understand you correctly you have a two digit year and want to convert that to a four digit year? That's not uniquely possible of course; by convention, as the documentation to strptime() says: > > > > On input, values 00 to 68 are prefixed by 20 and 69 to 99 by 19 ? that > > is the behaviour specified by the 2004 and 2008 POSIX standards... > > > > If this is correct for you, you need to convert the string to a time object and the time object back to string. The format specifier %Y prints four-digit years: > > > > > > d <- "7/27/59" > > strptime(d, format="%m/%d/%y") # "2059-07-27 EDT" > > x <- strptime(d, format="%m/%d/%y") > > > > strftime(x, format="%m/%d/%Y") # "07/27/1977" > > > > > > > > B. > > > > > > > > > > > > > > > > On Feb 3, 2016, at 11:03 AM, carol white via R-help <r-help at r-project.org> wrote: > > > >> Hi,might be trivial but how to determine the year of a date which is in the %m/%d/%y format and those whose year is century should be modified to ISO so that all date will have with year in ISO? > >> Regards, > >> Carol > >> > >> [[alternative HTML version deleted]] > >> > >> ______________________________________________ > >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > >> https://stat.ethz.ch/mailman/listinfo/r-help > >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > >> and provide commented, minimal, self-contained, reproducible code. > > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > >