[Chartjs]-Create ticks at certain time positions on a chartjs cartesian time axis

OK I found it. The property is in the time attribute:

time: {
  unit: "minute",
  unitStepSize: 10,
  displayFormats: {
    minute: "HH:mm"
  },
  min: firstprettyTime, // <- moment js object
},

All praise to this guy’s answer.