Modify ticks without specifying tick length

Question

I am making a ListPlot, in which the x-axis is the result of AbsoluteTime. I want the tick text to be human-readable by applying DateString, but don't want to mess with the automatic tick length. Is this possible? Thanks!

Answer 1

Unless you specify the tick mark length in your tick specifications tick marks are rendered with default length and style.

tickF = {#, DateString[#, {"MonthNameShort", " ", "Day", "/", "YearShort"}]} & /@ 
  AbsoluteTime /@ DateRange[##, {10, "Day"}] &;

Example data:

data = {{3368649600, 8}, {3369427200, 10}, {3370291200, 12}, {3370636800, 14}, 
  {3371673600, 15}, {3372537600, 20}};

If you have to use ListPlot:

ListPlot[data, Frame -> True, Axes -> False, PlotRange -> Full,
 FrameTicks -> {tickF, Automatic, Automatic, Automatic}, 
 GridLines -> {First /@ tickF[##] &, None}]

If not, DateListPlot is more convenient to use for your data structure:

DateListPlot[data, PlotRange -> Full, 
  FrameTicks -> {tickF, Automatic, Automatic, Automatic}]