Index: /trunk/dbconfig/stack.md
===================================================================
--- /trunk/dbconfig/stack.md	(revision 29282)
+++ /trunk/dbconfig/stack.md	(revision 29283)
@@ -49,4 +49,5 @@
     hostname           STR    64
     good_frac          F32    0.0     # Key
+    mjd_obs            F64    0.0
     fault              S16    0       # Key
     software_ver    STR         16
Index: /trunk/ippTools/src/stacktool.c
===================================================================
--- /trunk/ippTools/src/stacktool.c	(revision 29282)
+++ /trunk/ippTools/src/stacktool.c	(revision 29283)
@@ -982,4 +982,5 @@
     PXOPT_LOOKUP_STR(hostname, config->args, "-hostname", false, false);
     PXOPT_LOOKUP_F32(good_frac, config->args, "-good_frac", false, false);
+    PXOPT_LOOKUP_F64(mjd_obs, config->args, "-mjd_obs", false, false);
 
     PXOPT_LOOKUP_STR(ver_pslib, config->args, "-ver_pslib", false, false);
@@ -1047,4 +1048,5 @@
                                hostname,
                                good_frac,
+                               mjd_obs,
                                fault,
                                software_ver,
Index: /trunk/ippTools/src/stacktoolConfig.c
===================================================================
--- /trunk/ippTools/src/stacktoolConfig.c	(revision 29282)
+++ /trunk/ippTools/src/stacktoolConfig.c	(revision 29283)
@@ -172,4 +172,5 @@
     psMetadataAddStr(addsumskyfileArgs, PS_LIST_TAIL, "-hostname", 0,            "define hostname", 0);
     psMetadataAddF32(addsumskyfileArgs, PS_LIST_TAIL, "-good_frac",  0,            "define %% of good pixels", NAN);
+    psMetadataAddF64(addsumskyfileArgs, PS_LIST_TAIL, "-mjd_obs",  0,            "define mjd_obs (average mjd_obs of inputs)", NAN);
     psMetadataAddS16(addsumskyfileArgs, PS_LIST_TAIL, "-fault",  0,            "set fault code", 0);
     psMetadataAddS16(addsumskyfileArgs, PS_LIST_TAIL, "-quality",  0,            "set quality", 0);
Index: /trunk/ippconfig/recipes/ppStatsFromMetadata.config
===================================================================
--- /trunk/ippconfig/recipes/ppStatsFromMetadata.config	(revision 29282)
+++ /trunk/ippconfig/recipes/ppStatsFromMetadata.config	(revision 29283)
@@ -374,4 +374,5 @@
   ENTRY  VAL  GOOD_PIXEL_FRAC     F32  MEAN              -good_frac                     
   ENTRY  VAL  QUALITY             S32  CONSTANT          -quality             # Bad quality flag
+  ENTRY  VAL  MJD_OBS             F64  CONSTANT          -mjd_obs
 
   # Revision values
Index: /trunk/ppStack/src/ppStackConvolve.c
===================================================================
--- /trunk/ppStack/src/ppStackConvolve.c	(revision 29282)
+++ /trunk/ppStack/src/ppStackConvolve.c	(revision 29283)
@@ -295,4 +295,13 @@
         UPDATE_CONCEPT(unconvCell, "CELL.DARKTIME", NAN);
         UPDATE_CONCEPT(unconvFPA,  "FPA.ZP",        options->zp);
+
+        if (options->stats) {
+            psTime *fpaTime = psMetadataLookupPtr(NULL, outFPA->concepts, "FPA.TIME");
+            psTimeConvert(fpaTime, PS_TIME_TAI); // is this necessary??
+            double time = psTimeToMJD(fpaTime);
+            psMetadataAddF64(options->stats, PS_LIST_TAIL, "MJD_OBS", PS_META_DUPLICATE_OK,
+                                 "Average MJD_OBS of inputs", time);
+
+        }
     }