Determine if a variable contains a SAS date value

[LongTimer]

1. Test if value is a date-literal, or not.
2. Use the input-function, with the "??" option, and see if a missing-value is returned or not. Use the "ANY" informats, to sequentially test for valid date and date-time literal-values.
3. If a missing value is returned, assume the value is a SAS-date or SAS-datetime.
4. Test if the value is strictly a SAS-date, as follows: if(^('01JAN1960'd<=SasDate<=today()))
5. Use a similar test, to check for valid date-time values.

[Demoxe]

I guess it's too late to answer, but I think I've found an interesting solution.

You can get 1 observation from your initial table with the field in question, then set this field's value to current date and time or something like '31DEC9999:0:0:0'dt and then use function vvalue(field). If this field uses date format without time, then our datetime value will be too big for this format, so vvalue() will return the string, consisting from '*' characters. Otherwise vvalue() will return something, that resembles date and time. Depending on the output we can determine, was the field in question in date format or in datetime format. Code is below:

data _NULL_;

   set in_table;

   field='31DEC9999:0:0:0'dt;

   /* If the string consists only from '*' characters, then compress() below will return empty string */

   if compress(vvalue(field),'*')='' then call symput('date_format','date');

      else call symput('date_format','datetime');

run;