Можно бесконечно долго смотреть на .. две вещи

function OnInit (scriptPath)
  lu = require ("LuaUtil(lu)")
  ScriptDir, ScriptName = lu.SplitPath (scriptPath)
  DataPath = ScriptDir .. ScriptName ..".dat"
  message (DataPath)
end -- OnInit()

function dtToStr (dt)
  return type (dt) ~= "table" and "nil" or
    string.format ("%4d.%02d.%02d", dt.year, dt.month, dt.day)
end

function main()
  os.execute ("notepad.exe ".. DataPath)
  dofile (DataPath)
  DS, err = CreateDataSource (ClassCode, SecCode, INTERVAL_D1)
  if not DS then
    message ("err\n".. err)
    return
  end
  local ini, fin = 1, DS:Size()
  for i = 1, fin do
    local dt = dtToStr (DS:T(i))
    if dt >= IniDate then
      ini = i
      break
    end
  end
  local finPrice = DS:C(fin)
  local finDate  = DS:T(fin)
  local iniPrice = DS:C(ini)
  local iniDate  = DS:T(ini)
  local iniTime = os. <a name="cut"></a> time(iniDate)
  local finTime = os.time(finDate)
  local years = (finTime - iniTime) / (3600*24*365)
  local relPrice = finPrice / iniPrice
  message (dtToStr (iniDate) .." ".. tostring (iniPrice)
  .."\n".. dtToStr (finDate) .." ".. tostring (finPrice)
  .."\n".. iniTime .." ".. finTime
  .."\n".. string.format ("%.4f %.3f %.4f"
    ,years, relPrice, relPrice ^ (1/years)))
end -- main() 

local iniTime = os.time (iniDate)
  local finTime = os.time(finDate)