SAS informat datetime milliseconds

问题

Can SAS store and use datetimes that contain fractions of less than 1/10th of a second?

eg:

data _null_;
input @1 from_dt:datetime22.;
put from_dt= ;
cards;      
24Sep2009:11:21:19.856
;
run;

回答1:

A datetime variable is a numeric variable just like any other numeric variables. We just understand its value as the seconds since 01jan1960T00:00:00. Hope this helps.

data _null_;

  /* for date time, 1 means 1 sec since midnight jan 1st 1960 */
  dt = 1;
  put dt :datetime.;

  /* you can show the hundredth of second using datetime format */
  dt = 0.01;
  put dt :datetime19.2;

  /* but it is just a double type number. you can do
     what you want with the variable as with any other numeric
     variables */
  dt = 0.01;
  put "It was " dt :wordf15. "second after midnight.";
run;
/* on log
01JAN60:00:00:01
01JAN60:00:00:00.01
it was zero and 01/100 second after midnight.
*/

回答2:

Your sample code is rounding on the printed output. Adding a format (eg best32.) on the put statement shows that there is better precision being held...

data _null_; 
input @1 from_dt:datetime22.; 
put from_dt= best32.; 
cards;
24Sep2009:11:21:19.856 
; 
run; 

from_dt=1569410479.856

回答3:

As Rog pointed out, you can read in and store datetimes with more precision than .1 sec.

Just use the datetime22.3 or a similar format and informat instead of datetime22.

来源：https://stackoverflow.com/questions/1471229/sas-informat-datetime-milliseconds