diff --git a/src/common/backend/utils/adt/datetime.cpp b/src/common/backend/utils/adt/datetime.cpp
index 1a48d2d6c87b227edc85b842f81bf872d9d4164e..9369230fe1f26ffc2de751540dcf50a76efff510 100644
--- a/src/common/backend/utils/adt/datetime.cpp
+++ b/src/common/backend/utils/adt/datetime.cpp
@@ -3553,11 +3553,18 @@ void EncodeDateTime(struct pg_tm* tm, fsec_t fsec, bool print_tz, int tz, const
             *str++ = '-';
             str = pg_ultostr_zeropad_width_2(str, tm->tm_mday);
             *str++ = (style == USE_ISO_DATES) ? ' ' : 'T';
-            str = pg_ultostr_zeropad_width_2(str, tm->tm_hour);
-            *str++ = ':';
-            str = pg_ultostr_zeropad_width_2(str, tm->tm_min);
-            *str++ = ':';
-            str = AppendTimestampSeconds(str, tm, fsec);
+            if (tm->tm_hour || tm->tm_min || tm->tm_sec || fsec) {
+                str = pg_ultostr_zeropad_width_2(str, tm->tm_hour);
+                *str++ = ':';
+                str = pg_ultostr_zeropad_width_2(str, tm->tm_min);
+                *str++ = ':';
+                str = AppendTimestampSeconds(str, tm, fsec);
+            } else {
+                constexpr char TIME_ZERO[] = "00:00:00";
+                rc = memcpy_sp(str, MAXDATELEN + 1, TIME_ZERO, sizeof(TIME_ZERO));
+                securec_check(rc, "\0", "\0");
+                str += sizeof(TIME_ZERO) - 1;
+            }
             if (print_tz)
                 str = EncodeTimezone(str, tz, style);
             break;
diff --git a/src/common/backend/utils/adt/timestamp.cpp b/src/common/backend/utils/adt/timestamp.cpp
index e50717aa6a4aa1faf79f2f6dee904a3c5cff1ae5..f1bf6ca006e99161db8bdc649b37a5fab95e7190 100644
--- a/src/common/backend/utils/adt/timestamp.cpp
+++ b/src/common/backend/utils/adt/timestamp.cpp
@@ -126,7 +126,7 @@ typedef struct {
 } generate_series_timestamptz_fctx;
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
-static void EncodeSpecialTimestamp(Timestamp dt, char* str);
+void EncodeSpecialTimestamp(Timestamp dt, char* str);
 static Timestamp dt2local(Timestamp dt, int timezone);
 static void AdjustTimestampForTypmod(Timestamp* time, int32 typmod);
 static void AdjustIntervalForTypmod(Interval* interval, int32 typmod);
@@ -388,6 +388,20 @@ static void CheckNlsFormat()
     }
 }
 
+void timestamp_out(Timestamp ts, char* buf) {
+    pg_tm tm;
+    fsec_t fsec;
+
+    CheckNlsFormat();
+
+    if (TIMESTAMP_NOT_FINITE(ts))
+        EncodeSpecialTimestamp(ts, buf);
+    else if (timestamp2tm(ts, NULL, &tm, &fsec, NULL, NULL) == 0)
+        EncodeDateTime(&tm, fsec, false, 0, NULL, u_sess->time_cxt.DateStyle, buf);
+    else
+        ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("timestamp out of range")));
+}
+
 /* timestamp_out()
  * Convert a timestamp to external form.
  */
@@ -395,18 +409,9 @@ Datum timestamp_out(PG_FUNCTION_ARGS)
 {
     Timestamp timestamp = PG_GETARG_TIMESTAMP(0);
     char* result = NULL;
-    struct pg_tm tt, *tm = &tt;
-    fsec_t fsec;
     char buf[MAXDATELEN + 1];
 
-    CheckNlsFormat();
-
-    if (TIMESTAMP_NOT_FINITE(timestamp))
-        EncodeSpecialTimestamp(timestamp, buf);
-    else if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) == 0)
-        EncodeDateTime(tm, fsec, false, 0, NULL, u_sess->time_cxt.DateStyle, buf);
-    else
-        ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("timestamp out of range")));
+    timestamp_out(timestamp, buf);
 
     result = pstrdup(buf);
     PG_RETURN_CSTRING(result);
@@ -1564,7 +1569,7 @@ static void AdjustIntervalForTypmod(Interval* interval, int32 typmod)
 /* EncodeSpecialTimestamp()
  * Convert reserved timestamp data type to string.
  */
-static void EncodeSpecialTimestamp(Timestamp dt, char* str)
+void EncodeSpecialTimestamp(Timestamp dt, char* str)
 {
     int rc = 0;
     if (TIMESTAMP_IS_NOBEGIN(dt)) {
@@ -1861,7 +1866,12 @@ int timestamp2tm(Timestamp dt, int* tzp, struct pg_tm* tm, fsec_t* fsec, const c
         return -1;
 
     j2date((int)date, &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
-    dt2time(time, &tm->tm_hour, &tm->tm_min, &tm->tm_sec, fsec);
+
+    if (time == 0) {
+        tm->tm_hour = tm->tm_min = tm->tm_sec = *fsec = 0;
+    } else {
+        dt2time(time, &tm->tm_hour, &tm->tm_min, &tm->tm_sec, fsec);
+    }
 #else
     time = dt;
     TMODULO(time, date, (double)SECS_PER_DAY);
diff --git a/src/gausskernel/process/threadpool/knl_session.cpp b/src/gausskernel/process/threadpool/knl_session.cpp
index 030ff32e56939a1c7e3337ad9122c8240779004f..b9f43a02be7734eb6ec31322755bf204facc9a69 100755
--- a/src/gausskernel/process/threadpool/knl_session.cpp
+++ b/src/gausskernel/process/threadpool/knl_session.cpp
@@ -482,6 +482,7 @@ static void knl_u_utils_init(knl_u_utils_context* utils_cxt)
     utils_cxt->varcharoutput_buffer = (char*)palloc0(256);
     utils_cxt->numericoutput_buffer = (char*)palloc0(64);
     utils_cxt->dateoutput_buffer = (char*)palloc0(MAXDATELEN + 1);
+    utils_cxt->timestamp_output_buffer = (char*)palloc0(MAXDATELEN + 1);
 
     (void)syscalllockInit(&utils_cxt->deleMemContextMutex);
 
diff --git a/src/gausskernel/storage/access/common/printtup.cpp b/src/gausskernel/storage/access/common/printtup.cpp
index 89159a6a922e26dc52c2d72285ea692497f4caca..6e1ac734c0af110bdd951bffa6d1aff12ebadfec 100644
--- a/src/gausskernel/storage/access/common/printtup.cpp
+++ b/src/gausskernel/storage/access/common/printtup.cpp
@@ -1315,6 +1315,13 @@ void printtup(TupleTableSlot *slot, DestReceiver *self)
                             outputstr = output_date_out(DatumGetDateADT(attr));
                         }
                         break;
+                    case F_TIMESTAMP_OUT: {
+                        outputstr = u_sess->utils_cxt.timestamp_output_buffer;
+                        Timestamp ts = DatumGetTimestamp(attr);
+
+                        timestamp_out(ts, outputstr);
+                        break;
+                    }
                     default:
                         outputstr = OutputFunctionCall(&thisState->finfo, attr);
                         need_free = true;
diff --git a/src/include/knl/knl_session.h b/src/include/knl/knl_session.h
index 679a91b0c8e5f28eeeec76671d1211f5a87a31c7..771894b97e0596b982285a0bd3a5ca0fe8356622 100644
--- a/src/include/knl/knl_session.h
+++ b/src/include/knl/knl_session.h
@@ -707,6 +707,7 @@ typedef struct knl_u_utils_context {
     char* varcharoutput_buffer;
     char* numericoutput_buffer;
     char* dateoutput_buffer;
+    char* timestamp_output_buffer;
 
     syscalllock deleMemContextMutex;
 
diff --git a/src/include/utils/datetime.h b/src/include/utils/datetime.h
index 71a3a39bb3f3a0779e43d407e681e1ef22705b6c..5bbc27397d8937147cdb9c88552cd322f878a310 100644
--- a/src/include/utils/datetime.h
+++ b/src/include/utils/datetime.h
@@ -287,6 +287,7 @@ extern int DetermineTimeZoneOffset(struct pg_tm* tm, pg_tz* tzp);
 
 extern void EncodeDateOnly(struct pg_tm* tm, int style, char* str);
 extern void EncodeTimeOnly(struct pg_tm* tm, fsec_t fsec, bool print_tz, int tz, int style, char* str);
+extern void EncodeSpecialTimestamp(Timestamp dt, char* str);
 extern void EncodeDateTime(struct pg_tm* tm, fsec_t fsec, bool print_tz, int tz, const char* tzn, int style, char* str);
 extern void EncodeInterval(struct pg_tm* tm, fsec_t fsec, int style, char* str);
 
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index f2d02d82d90fd218f0eb78e48d5d4015c2473ec2..78d631db2a2e8e7c1924fd3f3a324239c674709c 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -280,6 +280,7 @@ extern TimestampTz time_t_to_timestamptz(pg_time_t tm);
 extern pg_time_t timestamptz_to_time_t(TimestampTz t);
 
 extern const char* timestamptz_to_str(TimestampTz t);
+void timestamp_out(Timestamp ts, char* buf);
 
 extern int tm2timestamp(struct pg_tm* tm, const fsec_t fsec, const int* tzp, Timestamp* dt);
 extern int timestamp2tm(Timestamp dt, int* tzp, struct pg_tm* tm, fsec_t* fsec, const char** tzn, pg_tz* attimezone);