force_zone!

# File lib/time.rb, line 119
    def force_zone!(t, zone, offset=nil)
      if zone_utc?(zone)
        t.utc
      elsif offset ||= zone_offset(zone)
        # Prefer the local timezone over the fixed offset timezone because
        # the former is a real timezone and latter is an artificial timezone.
        t.localtime
        if t.utc_offset != offset
          # Use the fixed offset timezone only if the local timezone cannot
          # represent the given offset.
          t.localtime(offset)
        end
      else
        t.localtime
      end
    end