31 Jul
2015
31 Jul
'15
9:06 a.m.
On Fri, Jul 31, 2015 at 11:36 AM, Carl Meyer
If you are constructing a datetime in the middle of July, you have no need to set this attribute, because there are no ambiguous times in the middle of July.
That's if you are lucky. I mentioned this example before: Ukraine moved the clock back one hour on 1990-07-01. That was not in the middle of July, but close. This introduced an ambiguous hour where both the first and the second hour were in DST. (Yes, they kept observing STD/DST on top of that change, so they had two ambiguous hours in 1990.)