28 %MACRO _timestamp(dt);
 
   30    %IF &dt= %THEN %LET dt=%sysfunc(datetime());
 
   31    %LET d=%sysfunc(datepart(&dt));
 
   32    %LET t=%sysfunc(timepart(&dt));
 
   33    %LET h=%sysfunc(hour(&t));
 
   34    %LET m=%sysfunc(minute(&t));
 
   35    %LET s=%sysfunc(second(&t));
 
   36    %sysfunc(putn(&d,yymmdd10.))-%sysfunc(putn(&h,z2.))-%sysfunc(putn(&m,z2.))-%sysfunc(putn(&s,z6.3))