       when 'months' , 'M' then d3.time.format("%b '%y")
       when 'weeks' , 'W'  then d3.time.format('%-m/%-d/%y')
       when 'days' , 'D' then d3.time.format('%a')
+      when 'seconds' , 'S' then d3.time.format('%M : %S')
       else d3.time.format('%Y')
   .property 'selectedInterval'
 

      when 'quarters', 'Q' then d3.time.months(start, stop, 3)
      when 'months', 'M' then @monthsBetween(start, stop)
      when 'weeks' , 'W'  then @weeksBetween(start, stop)

    return 0 if (labelledTicks.length < 2)


  weeksBetween: (start, stop, skip = 1) ->
    d3.time.weeks(start, stop).filter((d, i) -> !(i % skip))

  secondsBetween: (start, stop, skip = 1) ->
    d3.time.seconds(start, stop).filter((d, i) -> !(i % skip))

  # the weeks which should be labelled
  labelledWeeks: (start, stop) ->
    weeks = @weeksBetween(start, stop)
