[R] Strange behaviour of ISOdatetime

[Tony Plate]

Have you checked that that time exists in the time zone you are using?  From ?ISOdatetime:

Note
...
Remember that in most timezones some times do not occur and some occur twice because of transitions to/from summer time. What happens in those cases is OS-specific. 

You could try working out what your system is using as the transition to/from summer time.  (If you need to generate times that are 2 hours after midnight, try using ISOdatetime to generate the midnight times and add 2 hours).

On my system, all this works fine:

> ISOdatetime(1995,03,26,2,0,0)
[1] "1995-03-26 02:00:00 MST"
> ISOdatetime(1995,03,26,0,0,0) + 2 * 60 * 60
[1] "1995-03-26 02:00:00 MST"
> sessionInfo()
R version 2.8.1 (2008-12-22) 
i386-pc-mingw32 

locale:
LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States.1252;LC_MONETARY=English_United States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] TimeWarp_0.7    abind_1.2-0     trackObjs_0.8-0 tap.misc_1.0   
[5] bmc.misc_1.0    RtTests_0.1-5  
> 


-- Tony Plate

Pedro de Barros wrote:
> Hi All,
> 
> I am watching a strange behaviour of ISOdatetime. In my work computer, I 
> get NA when I try to do
>  > ISOdatetime(1995,03,26,2,0,0)
> [1] NA
> 
> But on other dates and/or times (hour) works OK
>  > ISOdatetime(1995,03,25,2,0,0)
> [1] "1995-03-25 02:00:00 GMT"
> 
> In my home computer, I do not have this problem.
> I am running the same version of R (2.8.1 patched) on both machines, the 
> same version of Gnu Emacs (22.3.1) and the same version of ESS (5.3.10). 
> Both are running Windows XP. Has anyone experienced this before?
> 
> Pedro
> 
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