diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 926358e..8a62d65 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -186,6 +186,8 @@ static const datetkn deltatktbl[] = {
 	{DDECADE, UNITS, DTK_DECADE},		/* "decade" relative */
 	{"decades", UNITS, DTK_DECADE},		/* "decades" relative */
 	{"decs", UNITS, DTK_DECADE},	/* "decades" relative */
+	{DFORTNIGHT, UNITS, DTK_FORTNIGHT}, /* "fortnights" relative */
+	{"fortnights", UNITS, DTK_FORTNIGHT}, /* "fortnights" relative */
 	{"h", UNITS, DTK_HOUR},		/* "hour" relative */
 	{DHOUR, UNITS, DTK_HOUR},	/* "hour" relative */
 	{"hours", UNITS, DTK_HOUR}, /* "hours" relative */
@@ -214,6 +216,8 @@ static const datetkn deltatktbl[] = {
 	{"msecs", UNITS, DTK_MILLISEC},
 	{"qtr", UNITS, DTK_QUARTER},	/* "quarter" relative */
 	{DQUARTER, UNITS, DTK_QUARTER},		/* "quarter" relative */
+	{DQUINZAINE, UNITS, DTK_QUINZAINE}, /* "quinzaines" relative */
+	{"quinzaines", UNITS, DTK_QUINZAINE}, /* "quinzaines" relative */
 	{"s", UNITS, DTK_SECOND},
 	{"sec", UNITS, DTK_SECOND},
 	{DSECOND, UNITS, DTK_SECOND},
@@ -3281,6 +3285,18 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						tmask = DTK_M(DAY);
 						break;
 
+					case DTK_FORTNIGHT:
+						tm->tm_mday += val * 14;
+						AdjustFractDays(fval, tm, fsec, 14);
+						tmask = DTK_M(WEEK);
+						break;
+
+					case DTK_QUINZAINE:
+						tm->tm_mday += val * 15;
+						AdjustFractDays(fval, tm, fsec, 15);
+						tmask = DTK_M(WEEK);
+						break;
+
 					case DTK_WEEK:
 						tm->tm_mday += val * 7;
 						AdjustFractDays(fval, tm, fsec, 7);
diff --git a/src/include/utils/datetime.h b/src/include/utils/datetime.h
index e9a1ece..3944912 100644
--- a/src/include/utils/datetime.h
+++ b/src/include/utils/datetime.h
@@ -52,6 +52,8 @@ struct tzEntry;
 #define DHOUR			"hour"
 #define DDAY			"day"
 #define DWEEK			"week"
+#define DFORTNIGHT		"fortnight"
+#define DQUINZAINE		"quinzaine"
 #define DMONTH			"month"
 #define DQUARTER		"quarter"
 #define DYEAR			"year"
@@ -181,6 +183,8 @@ struct tzEntry;
 #define DTK_TZ_MINUTE	35
 #define DTK_ISOYEAR		36
 #define DTK_ISODOW		37
+#define DTK_FORTNIGHT		38
+#define DTK_QUINZAINE		39
 
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c873a99..350f097 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -40,6 +40,18 @@ SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
  10 days 12:00:00
 (1 row)
 
+SELECT INTERVAL '1 fortnight' AS "Fourteen days";
+ Fourteen days 
+---------------
+ 14 days
+(1 row)
+
+SELECT INTERVAL '1 quinzaine' AS "Fifteen days";
+ Fifteen days 
+--------------
+ 15 days
+(1 row)
+
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
  One month 15 days 
 -------------------
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 789c3de..ae884bc 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -12,6 +12,8 @@ SELECT INTERVAL '-08:00' AS "Eight hours";
 SELECT INTERVAL '-1 +02:03' AS "22 hours ago...";
 SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
+SELECT INTERVAL '1 fortnight' AS "Fourteen days";
+SELECT INTERVAL '1 quinzaine' AS "Fifteen days";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";