Converting localTime to UTC in Pacific Time zone results in odd DST shifts

The code below, using today as the starting date, goes back one day at a time, converting localTime to UTC time in the Pacific Time zone.  This list should result in "1 hour" offsets in March and November, but this does not seem to be the case as follows (selected results - only when a change occurred):

Circumvention: change the timezone to Arizona.

Environment: AX 2012 CU6 running on Server 2012, Client is Win7: all set with Pacific Time zone.

Any cogent theories?

2015

localDateTime: 1/25/2015 01:09:12 pm    utcTime: 1/26/2015 01:09:12 am  (January?)

localDateTime: 1/24/2015 01:09:12 pm    utcTime: 1/25/2015 02:09:12 am

 

2014

localDateTime: 11/2/2014 01:09:12 pm    utcTime: 11/3/2014 02:09:12 am  (3hrs?)

localDateTime: 11/1/2014 01:09:12 pm    utcTime: 11/1/2014 05:09:12 pm

 

localDateTime: 3/9/2014 01:09:12 pm    utcTime: 3/9/2014 05:09:12 pm  (3hrs?)

localDateTime: 3/8/2014 01:09:12 pm    utcTime: 3/9/2014 01:09:12 am

 

localDateTime: 1/26/2014 01:09:12 pm    utcTime: 1/27/2014 01:09:12 am  (January?)

localDateTime: 1/25/2014 01:09:12 pm    utcTime: 1/26/2014 02:09:12 am

 

2013

localDateTime: 11/3/2013 01:09:12 pm    utcTime: 11/4/2013 02:09:12 am  (3hrs?)

localDateTime: 11/2/2013 01:09:12 pm    utcTime: 11/2/2013 05:09:12 pm

 

localDateTime: 3/10/2013 01:09:12 pm    utcTime: 3/10/2013 05:09:12 pm  (3hrs?)

localDateTime: 3/9/2013 01:09:12 pm    utcTime: 3/10/2013 01:09:12 am

 

localDateTime: 1/19/2013 01:09:12 pm    utcTime: 1/20/2013 01:09:12 am

localDateTime: 1/18/2013 01:09:12 pm    utcTime: 1/19/2013 02:09:12 am  (January?)

 

2012

localDateTime: 11/4/2012 01:09:12 pm    utcTime: 11/5/2012 02:09:12 am   (3hrs?)

localDateTime: 11/3/2012 01:09:12 pm    utcTime: 11/3/2012 05:09:12 pm

static void JMC_LocalDateTimeToUTC(Args _args)
{

utcDateTime localDateTime;
utcDateTime utcTime;
int x;

localDateTime = DateTimeUtil::applyTimeZoneOffset(DateTimeUtil::getSystemDateTime(), DateTimeUtil::getUserPreferredTimeZone());

for (x = 1; x < 1000; x++)
    {
    localDateTime = DateTimeUtil::addDays(localDateTime, -1);
    utcTime = DateTimeUtil::applyTimeZoneOffset(localDateTime,
    DateTimeUtil::getTimeZoneOffset(localDateTime, DateTimeUtil::getUserPreferredTimeZone()));
    info(strfmt("localDateTime: %1    utcTime: %2", localDateTime, utcTime));
    }
}