strftime (TZInfo::Timezone)

    # File lib/active_support/vendor/tzinfo-0.3.8/tzinfo/timezone.rb, line 448
        def strftime(format, utc = Time.now.utc)
          period = period_for_utc(utc)
          local = period.to_local(utc)
          local = Time.at(local).utc unless local.kind_of?(Time) || local.kind_of?(DateTime)
          abbreviation = period.abbreviation.to_s.gsub(/%/, '%%')

          format = format.gsub(/(.?)%Z/) do
            if $1 == '%'
              # return %%Z so the real strftime treats it as a literal %Z too
              '%%Z'
            else
              "#$1#{abbreviation}"
            end
          end

          local.strftime(format)
        end