feat: mf_dttm macro and associated test

base/mf_dttm.sas

@@ -0,0 +1,29 @@
+/**
+  @file
+  @brief Returns E8601DT26.6 if compatible else DATETIME19.3
+  @details Per our experience in [Data Controller for SAS]
+  (https://datacontroller.io) deployments, the E8601DT26.6 datetime format has
+  the widest support when it comes to pass-through SQL queries.
+
+  However, it is not supported in WPS or early versions of SAS 9 (M3 and below).
+
+
+  <h4> Related Macros </h4>
+  @li mf_dttm.test.sas
+
+  @author Allan Bowe
+**/
+
+%macro mf_dttm(
+)/*/STORE SOURCE*/;
+
+%if "&sysver"="9.2" or "&sysver"="9.3"
+  or ("&sysver"="9.4" and "%substr(&SYSVLONG,9,1)" le "3")
+  or "%substr(&sysver,1,1)"="4"
+  or "%substr(&sysver,1,1)"="5"
+%then %do;DATETIME19.3%end;
+%else %do;E8601DT26.6%end;
+
+%mend mf_dttm;
+
+