I got a chart created in AM Charts. There is a JSON structure for data send to chart. the problem is date output on chart is for some dates there is a mismatch for date output on the chart

window.chartData = [


{
    "date": "21-10-29",
    "value": "¥ 185"
  },
  {
    "date": "21-11-02",
    "value": "¥ 185"
  },
  {
    "date": "21-11-09",
    "value": "¥ 185"
  },
  {
    "date": "21-11-16",
    "value": "¥ 185"
  },
  {
    "date": "21-11-23",
    "value": "¥ 185"
  },
  {
    "date": "21-11-30",
    "value": "¥ 185"
  },
  {
    "date": "21-12-07",
    "value": "¥ 185"
  },
  {
    "date": "21-12-14",
    "value": "¥ 185"
  },
  {
    "date": "21-12-21",
    "value": "¥ 185"
  },
  {
    "date": "22-01-04",
    "value": "¥ 185"
  },
  {
    "date": "22-01-10",
    "value": "¥ 185"
  }
]

I got things set for the format like this chart.dateFormatter.inputDateFormat = 'yy-MM-dd'

Any clue?