Index: branches/pap/ippTools/src/difftool.c
===================================================================
--- branches/pap/ippTools/src/difftool.c	(revision 23690)
+++ branches/pap/ippTools/src/difftool.c	(revision 23723)
@@ -1275,10 +1275,17 @@
     PXOPT_COPY_STR(config->args, selectWhere, "-input_label", "inputWarpRun.label", "==");
     PXOPT_COPY_STR(config->args, selectWhere, "-template_label", "templateWarpRun.label", "==");
+    PXOPT_COPY_F32(config->args, selectWhere, "-rotdiff", "ABS(inputRawExp.posang - templateRawExp.posang)", "<=");
     PXOPT_COPY_F32(config->args, selectWhere, "-timediff",
                    "ABS(TIME_TO_SEC(TIMEDIFF(inputRawExp.dateobs, templateRawExp.dateobs)))", "<=");
-    PXOPT_COPY_F32(config->args, selectWhere, "-rotdiff", "ABS(inputRawExp.posang - templateRawExp.posang)", "<=");
+
     // Haversine formula for great circle distance
     PXOPT_COPY_F32(config->args, selectWhere, "-distance",
                    "DEGREES(2*ASIN(SQRT(POW(SIN(inputRawExp.decl - templateRawExp.decl),2) + COS(inputRawExp.decl)*COS(templateRawExp.decl)*POW(SIN(inputRawExp.ra - templateRawExp.ra),2))))", "<=");
+
+    PXOPT_LOOKUP_BOOL(backwards, config->args, "-backwards", false);
+
+    psMetadataAddF32(selectWhere, PS_LIST_TAIL,
+                     "TIME_TO_SEC(TIMEDIFF(inputRawExp.dateobs, templateRawExp.dateobs))",
+                     PS_META_DUPLICATE_OK, backwards ? "<" : ">", 0.0);
 
     // Restrictions for inserting skycells