diff --git a/core/modules/filters/eachday.js b/core/modules/filters/eachday.js
index 350830564..27a20ec3d 100644
--- a/core/modules/filters/eachday.js
+++ b/core/modules/filters/eachday.js
@@ -24,9 +24,16 @@ exports.eachday = function(source,operator,options) {
 		value = (new Date(value)).setHours(0,0,0,0);
 		return value+0;
 	};
+	// Convert ISO date string to Date object if needed.
+	var toDateObj = function(value) {
+		if(!(value instanceof Date)) {
+			value = new Date($tw.utils.parseDate(value));
+		}
+		return value;
+	};
 	source(function(tiddler,title) {
 		if(tiddler && tiddler.fields[fieldName]) {
-			var value = toDate(tiddler.fields[fieldName]);
+			var value = toDate(toDateObj(tiddler.fields[fieldName]));
 			if(values.indexOf(value) === -1) {
 				values.push(value);
 				results.push(title);
diff --git a/core/modules/filters/sameday.js b/core/modules/filters/sameday.js
index 478f56c90..c97f6c2f2 100644
--- a/core/modules/filters/sameday.js
+++ b/core/modules/filters/sameday.js
@@ -23,9 +23,16 @@ exports.sameday = function(source,operator,options) {
 	var isSameDay = function(dateField) {
 			return (new Date(dateField)).setHours(0,0,0,0) === targetDate;
 		};
+	// Convert ISO date string to Date object if needed.
+	var toDateObj = function(value) {
+		if(!(value instanceof Date)) {
+			value = new Date($tw.utils.parseDate(value));
+		}
+		return value;
+	};
 	source(function(tiddler,title) {
 		if(tiddler && tiddler.fields[fieldName]) {
-			if(isSameDay(tiddler.fields[fieldName])) {
+			if(isSameDay(toDateObj(tiddler.fields[fieldName]))) {
 				results.push(title);
 			}
 		}