By using the mentioned code i am getting this plot. Now i want x label tics at each month. How can i get it?

 t=datenum(2013,11,24):datenum(2015,06,19);
ax=plotyyy(t',sst,t',pco2,t',sss);
datetick('x','mmm-yy','keepticks')
set(ax(1),'XTick',[])

[Walter Roberson]

Which MATLAB version are you using? R2016b added nicer ways to do date plots.