[Rd] terribly annoying bug with POSIXlt : one o'clock is midnight?

Gavin Simpson gavin.simpson at ucl.ac.uk
Fri Feb 4 16:28:42 CET 2011


On Fri, 2011-02-04 at 16:21 +0100, Joris Meys wrote:
> Apparently, as.POSIXlt takes one o'clock as the start of the day :
> 
> > as.POSIXlt(0,origin="1970-01-01")
> [1] "1970-01-01 01:00:00 CET"
> > as.POSIXlt(0,origin="1970-01-01 00:00:00")
> [1] "1970-01-01 01:00:00 CET"
> > as.POSIXlt(0,origin="1970-01-01 23:59:59")
> [1] "1970-01-02 00:59:59 CET"
> 
> Cheers

Isn't this just a timezone thing? CET is an hour ahead of UTC (GMT)

> as.POSIXlt(0,origin="1970-01-01")
[1] "1970-01-01 01:00:00 BST"
> as.POSIXlt(0,origin="1970-01-01", tz = "GMT")
[1] "1970-01-01 GMT"
> as.POSIXlt(0,origin="1970-01-01 00:00:00")
[1] "1970-01-01 01:00:00 BST"
> as.POSIXlt(0,origin="1970-01-01 00:00:00", tz = "GMT")
[1] "1970-01-01 GMT"
> as.POSIXlt(0,origin="1970-01-01 23:59:59", tz = "GMT")
[1] "1970-01-01 23:59:59 GMT"

G
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