I'm attempting to move from LiveCharts and I have a custom label formatter to display elapsed time
in the format: DD:HH:mm:ss, where DD is elapsed number of days.

I have found how to do HH:mm:ss using the following:

      wpfGridGraphControl.plt.Ticks(dateTimeX: true, dateTimeFormatStringX: "HH:mm:ss");

I've looked at the available format strings: https://tinyurl.com/y86clj9k, but there is nothing that seems to help.

Is there any way to implement a truly custom format callback that is passed an x-axis value and returns a string to display at the tick mark?