diff --git a/src/core/s-mold.c b/src/core/s-mold.c
index 588f4a4b70..b1cae491e7 100644
--- a/src/core/s-mold.c
+++ b/src/core/s-mold.c
@@ -1095,7 +1095,7 @@ STOID Mold_Error(REBVAL *value, REB_MOLD *mold, REBFLG molded)
 
 	case REB_TIME:
 		//len = Emit_Time(value, buf, Punctuation[GET_MOPT(mold, MOPT_COMMA_PT) ? PUNCT_COMMA : PUNCT_DOT]);
-		Emit_Time(mold, value);
+		Emit_Time(mold, value, FALSE);
 		break;
 
 	case REB_DATE:
diff --git a/src/core/t-date.c b/src/core/t-date.c
index 1bbe75f1b7..abb335f099 100644
--- a/src/core/t-date.c
+++ b/src/core/t-date.c
@@ -95,6 +95,7 @@
 	REBYTE *bp = &buf[0];
 	REBINT tz;
 	REBYTE dash = GET_MOPT(mold, MOPT_SLASH_DATE) ? '/' : '-';
+	REBOOL iso = GET_MOPT(mold, MOPT_MOLD_ALL);
 	REBVAL val = *value;
 	value = &val;
 
@@ -111,21 +112,30 @@
 	if (VAL_TIME(value) != NO_TIME) Adjust_Date_Zone(value, FALSE);
 
 //	Punctuation[GET_MOPT(mold, MOPT_COMMA_PT) ? PUNCT_COMMA : PUNCT_DOT]
-
-	bp = Form_Int(bp, (REBINT)VAL_DAY(value));
-	*bp++ = dash;
-	memcpy(bp, Month_Names[VAL_MONTH(value)-1], 3);
-	bp += 3;
-	*bp++ = dash;
-	bp = Form_Int_Pad(bp, (REBINT)VAL_YEAR(value), 6, -4, '0');
-	*bp = 0;
-
+	if (iso) {
+		// use ISO8601 output
+		bp = Form_Int_Pad(bp, (REBINT)VAL_YEAR(value), 6, -4, '0');
+		*bp = '-';
+		bp = Form_Int_Pad(++bp, (REBINT)VAL_MONTH(value), 2, -2, '0');
+		*bp = '-';
+		bp = Form_Int_Pad(++bp, (REBINT)VAL_DAY(value), 2, -2, '0');
+		*bp = 0;
+	} else {
+		// use standard Rebol output
+		bp = Form_Int(bp, (REBINT)VAL_DAY(value));
+		*bp++ = dash;
+		memcpy(bp, Month_Names[VAL_MONTH(value) - 1], 3);
+		bp += 3;
+		*bp++ = dash;
+		bp = Form_Int_Pad(bp, (REBINT)VAL_YEAR(value), 6, -4, '0');
+		*bp = 0;
+	}
 	Append_Bytes(mold->series, cs_cast(buf));
 
 	if (VAL_TIME(value) != NO_TIME) {
 
-		Append_Byte(mold->series, '/');
-		Emit_Time(mold, value);
+		Append_Byte(mold->series, iso ? 'T' : '/');
+		Emit_Time(mold, value, iso);
 
 		if (VAL_ZONE(value) != 0) {
 
@@ -138,9 +148,13 @@
 			else
 				*bp++ = '+';
 
-			bp = Form_Int(bp, tz/4);
+			if(iso) {
+				bp = Form_Int_Pad(bp, tz / 4, 2, -2, '0');
+			} else {
+				bp = Form_Int(bp, tz / 4);
+			}
 			*bp++ = ':';
-			bp = Form_Int_Pad(bp, (tz&3) * 15, 2, 2, '0');
+			bp = Form_Int_Pad(bp, (tz & 3) * 15, 2, 2, '0');
 			*bp = 0;
 
 			Append_Bytes(mold->series, cs_cast(buf));
diff --git a/src/core/t-time.c b/src/core/t-time.c
index 73177f2486..f4744ffdb9 100644
--- a/src/core/t-time.c
+++ b/src/core/t-time.c
@@ -135,8 +135,11 @@
 
 /***********************************************************************
 **
-*/  void Emit_Time(REB_MOLD *mold, REBVAL *value)
+*/  void Emit_Time(REB_MOLD *mold, REBVAL *value, REBOOL iso)
 /*
+**	NOTE: 'iso' arg is padding hour to two digits.
+**	      It is used only when MOLDing datetime with /ALL refinement.
+**	      In this datetime case hour should not be over 24.
 ***********************************************************************/
 {
 	REB_TIMEF tf;
@@ -144,8 +147,12 @@
 
 	Split_Time(VAL_TIME(value), &tf); // loses sign
 
-	if (tf.s == 0 && tf.n == 0) fmt = "I:2";
-	else fmt = "I:2:2";
+	if(iso) {
+		fmt = "2:2:2";
+	} else {
+		if (tf.s == 0 && tf.n == 0) fmt = "I:2";
+		else fmt = "I:2:2";
+	}
 
 	if (VAL_TIME(value) < (REBI64)0) Append_Byte(mold->series, '-');
 	Emit(mold, fmt, tf.h, tf.m, tf.s, 0);
diff --git a/src/tests/units/date-test.r3 b/src/tests/units/date-test.r3
index f359540d1e..d35fcc4bae 100644
--- a/src/tests/units/date-test.r3
+++ b/src/tests/units/date-test.r3
@@ -8,19 +8,19 @@ Rebol [
 
 ~~~start-file~~~ "date"
 
-===start-group=== "ISO88601 subset"
-	--test-- "ISO88601 basic load"
+===start-group=== "ISO8601 subset"
+	--test-- "ISO8601 basic load"
 		--assert 8-Nov-2013/17:01 = load "2013-11-08T17:01"
 		--assert 8-Nov-2013/17:01 = load "2013-11-08T17:01Z"
 		--assert 8-Nov-2013/17:01+1:00 = load "2013-11-08T17:01+0100"
 		--assert 8-Nov-2013/17:01-1:00 = load "2013-11-08T17:01-0100"
 		--assert 8-Nov-2013/17:01+1:00 = load "2013-11-08T17:01+01:00"
-	--test-- "basic load of not fully standard ISO88601"
+	--test-- "basic load of not fully standard ISO8601"
 		--assert 8-Nov-2013/17:01 = load "2013/11/08T17:01"
 		--assert 8-Nov-2013/17:01 = load "2013/11/08T17:01Z"
 		--assert 8-Nov-2013/17:01+1:00 = load "2013/11/08T17:01+0100"
 		--assert 8-Nov-2013/17:01+1:00 = load "2013/11/08T17:01+01:00"
-	--test-- "Invalid ISO88601 dates"
+	--test-- "Invalid ISO8601 dates"
 		--assert error? try [load "2013-11-08T17:01Z0100"]
 		--assert error? try [load "2013/11/08T17:01Z0100"]
 
@@ -31,6 +31,14 @@ Rebol [
 
 ===end-group===
 
+===start-group=== "MOLD/ALL on date"
+;-- producing ISO8601 valid result (https://tools.ietf.org/html/rfc3339)
+	--test-- "MOLD/ALL on date"
+		--assert "2000-01-01T01:02:03" = mold/all 1-1-2000/1:2:3
+		--assert "2000-01-01T10:20:03" = mold/all 1-1-2000/10:20:3
+		--assert "0200-01-01T01:02:03" = mold/all 1-1-200/1:2:3
+		--assert "0200-01-01T01:02:03+02:00" = mold/all 1-1-200/1:2:3+2:0
+		--assert "0200-01-01T01:02:03+10:00" = mold/all 1-1-200/1:2:3+10:0
 
 ===end-group===