This is an addendum to DATETICK2 which allowed time axis re-labeling when the plot is zoomed or panned. Day of Year format sets were added to the time label formats.
x = [733043:pi/10:733043+2*365];
y = sin((x-733043)/30)+rand(size(x));
set(gcf,'color',[1 1 1]);
Then zoom or pan as needed and the time axis will update the tick marks.