Index: /issm/trunk-jpl/src/c/classes/Cfsurfacesquaretransient.cpp
===================================================================
--- /issm/trunk-jpl/src/c/classes/Cfsurfacesquaretransient.cpp	(revision 28100)
+++ /issm/trunk-jpl/src/c/classes/Cfsurfacesquaretransient.cpp	(revision 28101)
@@ -52,4 +52,12 @@
 	xMemCpy<bool>(this->passedflags,in_passedflags,this->num_datatimes);
 
+	#ifdef _ISSM_DEBUG_ 
+	for(int i=0;i<this->num_datatimes-1;i++){
+		if(this->datatimes[i+1]<=this->datatimes[i]){
+			_error_("time series is not in chronological order");
+		}
+	}
+	#endif
+
 	this->J = in_J;
 }
Index: /issm/trunk-jpl/src/m/classes/cfsurfacesquaretransient.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/cfsurfacesquaretransient.m	(revision 28100)
+++ /issm/trunk-jpl/src/m/classes/cfsurfacesquaretransient.m	(revision 28101)
@@ -57,5 +57,5 @@
 			end
 			md = checkfield(md,'fieldname','self.definitionstring','field',self.definitionstring,'values',OutputdefinitionStringArray);
-			md = checkfield(md,'fieldname','self.observations','field',self.observations,'size',[md.mesh.numberofvertices+1 NaN],'NaN',1,'Inf',1);
+			md = checkfield(md,'fieldname','self.observations','field',self.observations,'size',[md.mesh.numberofvertices+1 NaN],'NaN',1,'Inf',1,'timeseries',1);
 			md = checkfield(md,'fieldname','self.weights','field',self.weights,'size',[md.mesh.numberofvertices+1 NaN],'NaN',1,'Inf',1);