Modify time unit on zoom

On a time scale chart, as the chart is zoomed in, the time gets more accurate, but the time axis remains as the same time display unit as when the chart was first loaded. Ideally when zooming the chart would be able to recognise the new chart limits, re-calculate the unit to use (unless it’s explicitly specified already by the options), and use that to pick a display format.

https://www.chartjs.org/docs/latest/axes/cartesian/time.html#time-units

options: {
  scales: {
    xAxes: [{
      type: 'time',
      time: {
        unit: 'month', // This should change when zoomed
        displayFormats: {
          minute: 'h:mm a',
          month: 'MMM YYYY'
        }
      }
    }]
  }
}

[Techn1x]

If you need this functionality now, this could potentially be done manually in onZoom() if you have access to the chart instance to calculate the new min/max bounds yourself (note my PR that gives this access https://github.com/chartjs/chartjs-plugin-zoom/pull/178 ) and then set the new chart options then update the chart

[kurkle]

Closing, works as expected