Reformat date to datatime

[jmmedina25]

Hello, I'm trying to reformat a date (ddmmmyyy) to DATETIME.  The code I tried to use didn't work:

data WORK.DEMOS1;
set WORK.DEMOS;
DateofBirth1=input(DateofBirth,date9.);
format DateofBirth1 datetime16.;
run;

Does anyone know how to do this in a data step or proc sql step? Thanks!

[Tom · Accepted solution]

You cannot "reformat" a date to a datetime.  You need to convert the date value (number of days) to a datetime value (number of seconds).  Then you can use any of the many datetime formats to change how the number is displayed.  You must pick a time of day for the datetime value.  Most people use midnight (00:00:00).

data WORK.DEMOS1;
  set WORK.DEMOS;
  DateTimeofBirth=dhms(DateofBirth,0,0,0);
  format DateTimeofBirth datetime20.;
run;

Note: Do not display date or datetime values with only 2 digits for the year.

[novinosrin]

/*If DateofBirth is charatcer*/
data WORK.DEMOS1;
set WORK.DEMOS;
DateofBirth1=dhms(input(DateofBirth,date9.),0,0,0);
format DateofBirth1 datetime16.;
run;
/*If DateofBirth is numeric sas data*/
data WORK.DEMOS1;
set WORK.DEMOS;
DateofBirth1=dhms(DateofBirth,0,0,0);
format DateofBirth1 datetime16.;
run;