function plotutctai
t=caltomjd([1972,1,1]):caltomjd([2005,6,1]);
tt=(t-t(1))*24;
gut('newfigg','','',[600,400]);
ggt('newaxes','',[0.09,0.1,0.82,0.8],'taxis',t(1),'xlim',[tt(1),tt(end)],'ylim',[-40,0]);
for n=1:length(t)
    utc_tai(n)=prm_utc_tai(t(n));
end
h=plot(tt,utc_tai);
ylabel('UTC-TAI (sec)'); title('UTC-TAI History')
