Index: /tags/ipp-20130307/PS-IPP-PStamp/lib/PS/IPP/PStamp/Job.pm
===================================================================
--- /tags/ipp-20130307/PS-IPP-PStamp/lib/PS/IPP/PStamp/Job.pm	(revision 35506)
+++ /tags/ipp-20130307/PS-IPP-PStamp/lib/PS/IPP/PStamp/Job.pm	(revision 35507)
@@ -221,7 +221,17 @@
     if (!iszero($mjd_min)) {
         $dateobs_begin = mjd_to_dateobs($mjd_min);
+        if (!$dateobs_begin) {
+            $row->{error_code} = $PSTAMP_INVALID_REQUEST;
+            print STDERR "Invalid MJD_MIN: $mjd_min\n";
+            return undef;
+        }
     }
     if (!iszero($mjd_max)) {
         $dateobs_end = mjd_to_dateobs($mjd_max);
+        if (!$dateobs_begin) {
+            $row->{error_code} = $PSTAMP_INVALID_REQUEST;
+            print STDERR "Invalid MJD_MAX: $mjd_max\n";
+            return undef;
+        }
     }
     if (isnull($tess_id)) {
@@ -1327,4 +1337,9 @@
 sub mjd_to_dateobs {
     my $mjd = shift;
+
+    if ($mjd < 54000) {
+        print STDERR "MJD value too small minimum is 54000\n";
+        return undef; 
+    }
 
     my $ticks = ($mjd - 40587.0) * 86400;