Rather than calling datestr or datetick I recommend plotting using a datetime array as your X data.
v = 0:10;
y = v.^2;
tenDays = datetime('today') + days(v)
plot(tenDays, y)
As you zoom in on the axes MATLAB will automatically update the tick labels. If you want to customize the format used to display the datetime data you can use the xtickformat function to do so.
