[R] what is isdst parameter

[Jeff Newmiller]

1) Read the help file

?timezones

and note that the R project does not do any of the programming associated with that functionality.

2) Keep in mind that it is you who are supplying an indeterminate value to be interpreted. You need to know from context (another column of data? The trend of values preceding this value?) whether this value should be interpreted as DT or ST. You would have to convert first to POSIXlt and fix the isdst value yourself for those values that need your attention before converting to POSIXct.

3) Please read the posting guide and follow it, including posting in plain text on this mailing list.
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Sent from my phone. Please excuse my brevity.

On January 19, 2015 3:51:39 AM PST, Vasantha Kumar Kesavan <info.vasukv at gmail.com> wrote:
>Hi,
>
>Let me know, how to set/unset "isdst" parameter in system/session
>level.
>
>I could understand the possible values of isdst 0, 1 and -1.
>
>Example:
>
>Sys.setenv(TZ="PST8PDT");
>as.POSIXct("2007-11-04 01:00:00");
>
>when I was executed the above command,
>
>LINUX.X64 -> it was treated as PST value.
>[1] "2007-11-04 01:00:00 PST"
>
>WINDOWS.X64 -> it was treated as PDT value
>[1] "2007-11-04 01:00:00 PDT"
>
>SOLARIS.X64 -> it was treated as PST value.
>[1] "2007-11-04 01:00:00 PST"
>
>In 2007 the Daylight saving time was ended at 2007-11-04 02:00:00, so
>there
>was two "2007-11-04 01:00:00" values each for Standard and Daylight
>time.
>
>But I was not able to understand, how R is displaying the datetime as
>PST/PDT.
>
>Please do the needful.
>
>
>Thanks
>Vasanth
>
>	[[alternative HTML version deleted]]
>
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