Chartjs-Chartjs scatter chart's x axis is heavily padded

Got it!

Since all of my x values are multiples of 3600 (one hour in seconds) I was able to set the x axis stepSize to 3600 to make sure it begins and ends on a step.

    scales: {
      xAxes: [
        {
          ticks: {
            stepSize: 3600
          }
        }
      ],
    }