Datetick Zoom, Pan & Subplot with Day of Year

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.

Example:
x = [733043:pi/10:733043+2*365];
y = sin((x-733043)/30)+rand(size(x));
figure;plot(x,y,'-o');
grid on
set(gcf,'color',[1 1 1]);
datetick2_doy('x',34);

Then zoom or pan as needed and the time axis will update the tick marks.