# File lib/core/facets/time/change.rb, line 16
  def change(options)
    opts=options; #{}; 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[:sec]) ? 0 : self.usec)
    )
  end