I was doing some testing comparing ZoneInfo results to system timezone (using Pacific/Auckland) and found this discrepancy which is probably a bug.
I have this test case:
Expected: 2009-09-27 03:00:00.000
But was: 2009-09-27 02:00:00.000
This has to do with daylight saving time transition. Here's some background
NZ offsite is +12 hours
And the DST rule is: From 30 April 2007, DST (+1h) begins at 02:00 NZST on the last Sunday in September each year, and ends at 03:00 NZDT (or 02:00 NZST) on the first Sunday in April (http://home.tiscali.nl/~t876506/TZworld.html#pac
So this means at 2am on 2009-09-27 time gets moved to 3am.