R help - May 2010 - System neutral Daylight Savings Time response?

I'm searching for an r command that will notify me if I create a time that
does not exist due to Daylight Savings Time. For example, if I run the
following command on a windows machine
> ISOdatetime(2010,03,14,2,10,0, tz = "") # My system time is set
to the
United States Central Time Zone
[1] NA

R returns NA, which is the behavior I want. However, if I run the same
command on a mac, R returns a POSIXct object and I have to examine the
object manually to notice that I had tried to create an impossible time.

ISOdatetime(2010,03,14,2,10,0, tz = "")
[1] "2010-03-14 01:10:00 CST"

Is there a method of creating time objects in R that will always return NA
for non-existant times, no matter the operating system?

Thank you sincerely,
Garrett

	[[alternative HTML version deleted]]

Perhaps you should be using the chron package.  It has no time zones
in the first place.

On Mon, May 10, 2010 at 2:26 PM, Garrett Grolemund <gg7 at rice.edu>
wrote:
> I'm searching for an r command that will notify me if I create a time
that
> does not exist due to Daylight Savings Time. For example, if I run the
> following command on a windows machine
>
>> ISOdatetime(2010,03,14,2,10,0, tz = "") # My system time is
set to the
> United States Central Time Zone
> [1] NA
>
> R returns NA, which is the behavior I want. However, if I run the same
> command on a mac, R returns a POSIXct object and I have to examine the
> object manually to notice that I had tried to create an impossible time.
>
> ISOdatetime(2010,03,14,2,10,0, tz = "")
> [1] "2010-03-14 01:10:00 CST"
>
> Is there a method of creating time objects in R that will always return NA
> for non-existant times, no matter the operating system?
>
> Thank you sincerely,
> Garrett
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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