AndroidPlot, setting up various DomainValueFormats

I am trying to do the following for x-tags on my graph.

The first label should be in the format:

plot.getGraphWidget()
        .setDomainValueFormat(new SimpleDateFormat("dd/MM/yyyy hh:mm:ss"));

All other marks should show only minutes and seconds:

plot.getGraphWidget()
        .setDomainValueFormat(new SimpleDateFormat("mm:ss"));

I can set the format for all labels, but I cannot figure out how to change it only for the first label. My graph is dynamic and changes every second (new data is updated every second with a new value).

Perhaps there is a feature that can help me? (All of this is a little hard to find when the site is down ...) Or any other tips?

Any help is greatly appreciated.