[R] as.Date question

[MAL]

Mark, not sure that's the answer.

Usually one has x=y --> f(x)=f(y)

which doesn't seem to hold here (put x=zzz1, y=zzz2, f=as.Date()).

Or do I overlook something?


----- Original Message ----- 
From: "Marek Janad" <marek.janad at gmail.com>
To: <r-help at r-project.org>
Sent: Thursday, December 24, 2009 00:08
Subject: Re: [R] as.Date question


> Look at documentation
>
> ?as.Date
>
> as.Date first represents time in UTC, what gives:
>
> as.POSIXlt(zzz1, tz="UTC")
>
> HTH
>
> 2009/12/20 MAL <diverses at univecom.ch>:
>> All!
>>
>> This piece of code:
>>
>> zzz1 <- as.POSIXct("1999-03-18", tz="CET")
>> zzz2 <- as.POSIXlt("1999-03-18", tz="CET")
>> zzz1 == zzz2
>> as.Date(zzz1)
>> as.Date(zzz2)
>>
>> yields TRUE for "zzz1==zzz2", but the two dates returned by as.Date are
>> different:
>>
>>> as.Date(zzz1)
>>
>> [1] "1999-03-17"
>>>
>>> as.Date(zzz2)
>>
>> [1] "1999-03-18"
>>
>> I'm using R 2.10.0.
>>
>> Would be glad for any clarifications. Thanks!
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>>
>
>
>
> -- 
> Marek
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.