[R] Unexpected date format coercion

[PIKAL Petr]

Hi

Maybe you could inspect

parse_date_time {lubridate}	R Documentation

from package lubridate.

Or see answers here

https://stackoverflow.com/questions/25463523/how-to-convert-variable-with-mixed-date-formats-to-one-format

Cheers
Petr

> -----Original Message-----
> From: Jeremie Juste <jeremiejuste using gmail.com>
> Sent: Thursday, July 1, 2021 11:00 AM
> To: PIKAL Petr <petr.pikal using precheza.cz>
> Cc: r-help <r-help using r-project.org>
> Subject: Re: [R] Unexpected date format coercion
>
> Hello
>
> On Thursday,  1 Jul 2021 at 08:25, PIKAL Petr wrote:
> > Hm.
> >
> > Seems to me, that both your codes are wrong but printing in Linux is
> > different from Windows.
> >
> > With
> > as.Date("20-12-2020","%Y-%m-%d")
> > you say that 20 is year (actually year 20) and 2020 is day and only
> > first two values are taken (but with some valueas result is NA)
> >
> > I can confirm 4.0.3 in Windows behaves this way too.
> >> as.Date("20-12-2020","%Y-%m-%d")
> > [1] "0020-12-20"
>
> Many thanks for confirming this.
>
>
> On Thursday,  1 Jul 2021 at 18:22, Jim Lemon wrote:
> > Hi Jeremie,
> > Try:
> >
> > as.Date("20-12-2020","%y-%m-%d")
> > [1] "2020-12-20"
>
> Thanks for this info. I'm looking for something that produce NA if the date 
> is
> not exactly in the specified format so that it can be corrected. I was 
> relying on
> the format parameter of the date for that.
>
> The issue is that there can be so many variations in date format that for 
> the
> time being I still find it easier to delegate the correction to the user. A
> particular nasty case is when there are multiple date format in the same
> column.
>
>
> Best regards,
> Jeremie