ChartJS only shows milliseconds in runtime instead of date

Hiya,

I'm making a dashboard with, for now, one ChartJS line graph on it, displaying amounts over time. Thing is, the ticks on the x-axis show as milliseconds, instead of the actual date of the data point.

How, and especially where, can I change the format of the ticks for the ChartJS widget?

Thanks in advance,

Bart