documenting quirky behavior of as.POSIXct, as.POSIX.lt regarding AM/PM, possibly other cases
Also works as expected on the MacOSX 64 bit binary for R 2.8.1 (patched).
On May 5, 2009, at 4:06 PM, jim holtman wrote:
Seems to work fine for me on R 2.9.0:
as.POSIXct("2009/03/26 01:00:00 AM" , format="%Y/%m/%d %I:%M:%S %p" )
[1] "2009-03-26 01:00:00 GMT"
as.POSIXct("2009/03/26 01:00:00 PM" , format="%Y/%m/%d %I:%M:%S %p" )
[1] "2009-03-26 13:00:00 GMT"
On Tue, May 5, 2009 at 2:55 PM, Galkowski, Jan <jgalkows at akamai.com> wrote:
I wanted to put this on the R Wiki, but found the suitable pages were read-only. I wanted to get it out in public to save people work. I was converting dates like "2009/03/26 01:00:00 AM" using as.POSIXct. I found that using a format of "%Y/%m/%d %I:%M:%S %p" did not work correctly to distinguish AM from PM. Both were converted into the same timestamp. Indeed, what I found worked was affixing a space after the string timestamp to produce "2009/03/26 01:00:00 AM " or "2009/03/26 01:00:00 PM ". That works. Didn't see this documented in the associated pages anywhere. I wonder if the help system might benefit from user comments like for instance PHP has?
-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
David Winsemius, MD Heritage Laboratories West Hartford, CT