diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 31bdb37c55..edeaee4cb1 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -4651,20 +4651,12 @@ timestamp_part(PG_FUNCTION_ARGS)
 
 			case DTK_DOW:
 			case DTK_ISODOW:
-				if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
-					ereport(ERROR,
-							(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-							 errmsg("timestamp out of range")));
 				result = j2day(date2j(tm->tm_year, tm->tm_mon, tm->tm_mday));
 				if (val == DTK_ISODOW && result == 0)
 					result = 7;
 				break;
 
 			case DTK_DOY:
-				if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
-					ereport(ERROR,
-							(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-							 errmsg("timestamp out of range")));
 				result = (date2j(tm->tm_year, tm->tm_mon, tm->tm_mday)
 						  - date2j(tm->tm_year, 1, 1) + 1);
 				break;
@@ -4855,20 +4847,12 @@ timestamptz_part(PG_FUNCTION_ARGS)
 
 			case DTK_DOW:
 			case DTK_ISODOW:
-				if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
-					ereport(ERROR,
-							(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-							 errmsg("timestamp out of range")));
 				result = j2day(date2j(tm->tm_year, tm->tm_mon, tm->tm_mday));
 				if (val == DTK_ISODOW && result == 0)
 					result = 7;
 				break;
 
 			case DTK_DOY:
-				if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
-					ereport(ERROR,
-							(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-							 errmsg("timestamp out of range")));
 				result = (date2j(tm->tm_year, tm->tm_mon, tm->tm_mday)
 						  - date2j(tm->tm_year, 1, 1) + 1);
 				break;