def frequency

      return brute_frequency unless @seconds && @seconds.length > 1

      secs = toa(@seconds)

      secs[1..-1].inject([ secs[0], 60 ]) { |(prev, delta), sec|
        d = sec - prev
        [ sec, d < delta ? d : delta ]
      }[1]
    end
def frequency

      return brute_frequency unless @seconds && @seconds.length > 1

      secs = toa(@seconds)

      secs[1..-1].inject([ secs[0], 60 ]) { |(prev, delta), sec|
        d = sec - prev
        [ sec, d < delta ? d : delta ]
      }[1]
    end
Returns a quickly computed approximation of the frequency for this
 cron line.

 #brute_frequency, on the other hand, will compute the frequency by
 examining a whole year, that can take more than seconds for a seconds
 level cron...