Index: /trunk/ippTools/src/pxinject.c
===================================================================
--- /trunk/ippTools/src/pxinject.c	(revision 10230)
+++ /trunk/ippTools/src/pxinject.c	(revision 10231)
@@ -126,5 +126,11 @@
             return false;
         }
-        dateobs = psTimeFromISO(dateobsStr, PS_TIME_UTC);
+        // pass through NULL as this is an optional field
+        if (dateobsStr) {
+            dateobs = psTimeFromISO(dateobsStr, PS_TIME_UTC);
+        } else {
+            dateobs = NULL;
+        }
+
     }
 
Index: /trunk/ippTools/src/regtool.c
===================================================================
--- /trunk/ippTools/src/regtool.c	(revision 10230)
+++ /trunk/ippTools/src/regtool.c	(revision 10231)
@@ -1034,5 +1034,10 @@
             return false;
         }
-        dateobs = psTimeFromISO(dateobsStr, PS_TIME_UTC);
+        // pass through NULL as this is an optional field
+        if (dateobsStr) {
+            dateobs = psTimeFromISO(dateobsStr, PS_TIME_UTC);
+        } else {
+            dateobs = NULL;
+        }
     }