r strptime (R version 3.2.2 )

Question

Using strptime for text strings with a "AM or PM" worked fine in R version 3.0.2

> strptime("8/25/2015 6:38:41 PM", "%m/%d/%Y %I:%M:%S %p")
[1] "2015-08-25 18:38:41"

I recently upgraded to R 3.2.2 and now find this commend returns a NA:

>strptime("8/25/2015 6:38:41 PM", "%m/%d/%Y %I:%M:%S %p")
[1] NA

It appears to be something to do with the "PM". If I remove the "PM" and use the command as follows, it works (but of course it interprets as AM not PM):

>strptime("8/25/2015 6:38:41", "%m/%d/%Y %H:%M:%S")
[1] "2015-08-25 06:38:41 NZST"

What am I missing here?

Update:

Thanks all for your comments:

I reinstalled R 3.2.2 but got the same error

>  strptime("8/25/2015 6:38:41 PM", "%m/%d/%Y %I:%M:%S %p")
[1] NA

and here is the session info as requested

>  sessionInfo()
R version 3.2.2 (2015-08-14)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=English_New Zealand.1252  LC_CTYPE=English_New Zealand.1252   
[3] LC_MONETARY=English_New Zealand.1252 LC_NUMERIC=C                        
[5] LC_TIME=English_New Zealand.1252    

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

Then I changed the locale as suggested in a related post

> Sys.setlocale(category="LC_TIME","C")
[1] "C"
> strptime("8/25/2015 6:38:41 PM", "%m/%d/%Y %I:%M:%S %p")
[1] "2015-08-25 18:38:41 NZST"

And it worked - but does this mean I have to change the locale each time I want to convert a text time into a POSIXct class?

Answer 1

Try lubridate from hadleyverse

library(lubridate)
arrive <- ymd_hms("2011-06-04 12:00:00", tz = "Pacific/Auckland")
arrive
## [1] "2011-06-04 12:00:00 NZST"

https://cran.r-project.org/web/packages/lubridate/vignettes/lubridate.html