This is a rope. Don't push it. Been there, been swatted.
The current structure of R cannot support vectors of POSIXt timestamps
that have different tzones in different elements. You can keep a parallel
vector of tzones separately and manage environment variable TZ as needed
if you really must handle each timestamp in a different time zone.
By the way, count yourself lucky that c() works with POSIXlt at all, since
POSIXlt is a list of vectors. My practice is to store data in POSIXct
pretty much exclusively, reserving POSIXlt for temporary time
manipulations only.
On Mon, 23 Jun 2014, Marc Girondot wrote:
> When two POSIXlt objects are combine with c(), they lost their tzone
> attribute, even if they are the same.
> I don't know if it is a feature, but I don't like it !
>
> Marc
>
>> es <- strptime("2010-02-03 10:20:30", format="%Y-%m-%d %H:%M:%S", tz="UTC")
>> es
> [1] "2010-02-03 10:20:30 UTC"
>> attributes(es)
> $names
> [1] "sec" "min" "hour" "mday" "mon" "year" "wday" "yday" "isdst"
>
> $class
> [1] "POSIXlt" "POSIXt"
>
> $tzone
> [1] "UTC"
>
>> c(es, es)
> [1] "2010-02-03 11:20:30 CET" "2010-02-03 11:20:30 CET"
>> attributes(c(es, es))
> $names
> [1] "sec" "min" "hour" "mday" "mon" "year" "wday" "yday"
> "isdst" "zone" "gmtoff"
>
> $class
> [1] "POSIXlt" "POSIXt"
>
> $tzone
> [1] "" "CET" "CEST"
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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