MATLAB: Plotting Time on Xaxis - overlapping label
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I am having difficulties on plotting time on the xaxis. I have some overlapping labels. See below:

![plot][1]


  [1]: http://i.stack.imgur.com/Hwoyi.jpg

This is my code:

    time=datenum(0,0,0,0,0,timeinseconds);
    labs=1:10:length(time);
    
    figure(3);
    plotyy(time,xvalue,time,dens);
    datetick('x','HH:MM');
    set(gca,'XTick',time(labs),'XTickLabel',time(labs)); 
    legend('xval','CDF');
    title('Crash on Oct.10 2008 at 15:59pm');
    xlabel('Time');

First, why are the labels overlapping with the old ones? And secondly, how I can get the label to rotate 90degrees? I tried some other matlab functions to turn the labels but none seem able to tackle time format labels. 
