[R] Problem with as.POSIXlt$hour

David Winsemius dwinsemius at comcast.net
Tue Jun 15 15:54:17 CEST 2010

On Jun 15, 2010, at 7:45 AM, PtitBleu wrote:

> Hello,
> In one of my functions, I need to extract the hour from a date.
> For example:
> as.POSIXlt("2010-03-27 02:00:00")$hour gives 2 as expected.
> It works for all the dates I've tested except the following one  
> which is in
> my list of dates:
> as.POSIXlt("2010-03-28 02:00:00")$hour which gives 0.
> I don't understand why it doesn't work with this particular date.

It "works" for me with a result of 2, so I suspect it has something to  
do with whether that hour even "exists" during the shift from  
"ordinary" time to daylight savings time in your LOCALE (which was not  
offered but would be plausibly near GMT/UMT given the domain from  
which you are posting).
> Any idea ?
> Thanks in advance,
> Ptit Bleu (with R 2.9.0 under Windows ).   ...

... wrong info for this question, I suspect.

David Winsemius, MD
West Hartford, CT

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