>
> It appears that in 2.2.0 is correct according to the UK Government: https://www.gov.uk/when-do-the-clocks-change.
>
> Having discussed this in IRC it would appear that 2.2.1's behaviour is the same as in 2.0.0 and 2.1.5.
>
> I tested both with version 1.2.2 of the tzinfo gem installed.
>

On switch from BST to GMT times from Time.new(2013, 10, 27, 1, 0) to
Time.new(2013, 10, 27, 1, 59) are ambiguous - in local time 1:30 am
refers to one of 2 points in time. So the dst? method  is correct in
both cases, it's the localtime method that is resolving the ambiguity
differently. I don't think either is more valid that the other
although switching back and forth is probably not helpful

Fred