Plot: how to have the y-range automatically scale to min-max on the x-range?

Question

I have a long list of {date,value}.

I would like to use DateListPlot to plot only a subrange, from date1 to date2, with the range on the y-axis automatically chosen to be between the min and max value between those two dates (i.e. trivial automatic zooming).

I am sure Mathematic will do it with a simple option choice, but I must be dumb and cannot find it.

Can you help?

Thanks.

PS: here is simple code to show the issue using financial data:

spx = FinancialData["SP500", All];

DateListPlot[spx, 
 PlotRange -> {{{1987, 10, 1}, {1987, 11, 30}}, Automatic}, 
 PlotLegends -> Placed[namesFrom83, {Left, Bottom}], 
 PlotLabel -> "1987"]

Answer 1

I rather define my own filter to get new data and put it into DateListPlot:

iDateFilter[data_, st_, end_] :=
 Block[{is, ie},
  is = Position[spx, x_ /; AbsoluteTime[x[[1]]] >= AbsoluteTime[st], {1}, 1, 
     Heads -> False];
  ie = Position[spx, x_ /; AbsoluteTime[end] <= AbsoluteTime[x[[1]]], {1}, 1, 
    Heads -> False];
  Take[data, Flatten[{is, ie}]]
 ]

DateListPlot[iDateFilter[spx, {1987, 10, 1}, {1987, 11, 30}], 
 PlotLabel -> "1987"]

Answer 2

Using spx as defined:

With[{min = Min[spx[[;; , 2]]], max = Max[spx[[;; , 2]]]},
 DateListPlot[spx, 
  PlotRange -> {{{1987, 10, 1}, {1987, 11, 30}}, {0.9 min, 1, 1 max}},
   PlotLabel -> "1987", Joined -> True]]   

(omitting label):

Care may be needed if other datasets have missing values.