diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dec2fad..460c620 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -2281,8 +2281,8 @@ DecodeTimeOnly(char **field, int *ftype, int nf,
 	/* timezone not specified? then use session timezone */
 	if (tzp != NULL && !(fmask & DTK_M(TZ)))
 	{
-		struct pg_tm tt,
-				   *tmp = &tt;
+		static struct pg_tm tt;
+		struct pg_tm *tmp = &tt;
 
 		/*
 		 * daylight savings time modifier but no standard timezone? then error
@@ -2291,7 +2291,17 @@ DecodeTimeOnly(char **field, int *ftype, int nf,
 			return DTERR_BAD_FORMAT;
 
 		if ((fmask & DTK_DATE_M) == 0)
-			GetCurrentDateTime(tmp);
+		{
+			static TimestampTz cached_txts;
+			TimestampTz cur_txts = GetCurrentTransactionStartTimestamp();
+
+			// Only fetch the struct pg_tm if the tx timestamp is changed
+			if (cached_txts != cur_txts)
+			{
+				cached_txts = cur_txts;
+				GetCurrentDateTime(tmp);
+			}
+		}
 		else
 		{
 			/* a date has to be specified */