    # File lib/facets/core/time/change.rb, line 10
      def change(options)
        opts={}; options.each_pair{ |k,v| opts[k] = v.to_i }
        self.class.send( self.utc? ? :utc : :local,
          opts[:year]  || self.year,
          opts[:month] || self.month,
          opts[:day]   || self.day,
          opts[:hour]  || self.hour,
          opts[:min]   || (opts[:hour] ? 0 : self.min),
          opts[:sec]   || ((opts[:hour] || opts[:min]) ? 0 : self.sec),
          opts[:usec]  || ((opts[:hour] || opts[:min] || opts[:usec]) ? 0 : self.usec)
        )
      end