Clean up the ancient decision to show only two fractional-seconds digits

in "postgres_verbose" intervalstyle, and the equally arbitrary decision to
show at least two fractional-seconds digits in most other datetime display
styles.  This results in some minor changes in the expected regression test
outputs.

Also, coalesce a lot of repetitive code in datetime.c into subroutines,
for clarity and ease of maintenance.  In particular this roughly halves
the number of #ifdef HAVE_INT64_TIMESTAMP segments.

Ron Mayer, with some additional kibitzing from Tom Lane

src/test/regress/expected/horology.out

@@ -423,9 +423,9 @@ SELECT '' AS "64", d1 + interval '1 year' AS one_year FROM TIMESTAMP_TBL;
     | Tue Feb 10 17:32:01 1998
     | Tue Feb 10 17:32:01 1998
     | Tue Feb 10 17:32:02 1998
-    | Tue Feb 10 17:32:01.40 1998
-    | Tue Feb 10 17:32:01.50 1998
-    | Tue Feb 10 17:32:01.60 1998
+    | Tue Feb 10 17:32:01.4 1998
+    | Tue Feb 10 17:32:01.5 1998
+    | Tue Feb 10 17:32:01.6 1998
     | Fri Jan 02 00:00:00 1998
     | Fri Jan 02 03:04:05 1998
     | Tue Feb 10 17:32:01 1998
@@ -493,9 +493,9 @@ SELECT '' AS "64", d1 - interval '1 year' AS one_year FROM TIMESTAMP_TBL;
     | Sat Feb 10 17:32:01 1996
     | Sat Feb 10 17:32:01 1996
     | Sat Feb 10 17:32:02 1996
-    | Sat Feb 10 17:32:01.40 1996
-    | Sat Feb 10 17:32:01.50 1996
-    | Sat Feb 10 17:32:01.60 1996
+    | Sat Feb 10 17:32:01.4 1996
+    | Sat Feb 10 17:32:01.5 1996
+    | Sat Feb 10 17:32:01.6 1996
     | Tue Jan 02 00:00:00 1996
     | Tue Jan 02 03:04:05 1996
     | Sat Feb 10 17:32:01 1996
@@ -668,9 +668,9 @@ SELECT '' AS "64", d1 + interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
     | Tue Feb 10 17:32:01 1998 PST
     | Tue Feb 10 17:32:01 1998 PST
     | Tue Feb 10 17:32:02 1998 PST
-    | Tue Feb 10 17:32:01.40 1998 PST
-    | Tue Feb 10 17:32:01.50 1998 PST
-    | Tue Feb 10 17:32:01.60 1998 PST
+    | Tue Feb 10 17:32:01.4 1998 PST
+    | Tue Feb 10 17:32:01.5 1998 PST
+    | Tue Feb 10 17:32:01.6 1998 PST
     | Fri Jan 02 00:00:00 1998 PST
     | Fri Jan 02 03:04:05 1998 PST
     | Tue Feb 10 17:32:01 1998 PST
@@ -739,9 +739,9 @@ SELECT '' AS "64", d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
     | Sat Feb 10 17:32:01 1996 PST
     | Sat Feb 10 17:32:01 1996 PST
     | Sat Feb 10 17:32:02 1996 PST
-    | Sat Feb 10 17:32:01.40 1996 PST
-    | Sat Feb 10 17:32:01.50 1996 PST
-    | Sat Feb 10 17:32:01.60 1996 PST
+    | Sat Feb 10 17:32:01.4 1996 PST
+    | Sat Feb 10 17:32:01.5 1996 PST
+    | Sat Feb 10 17:32:01.6 1996 PST
     | Tue Jan 02 00:00:00 1996 PST
     | Tue Jan 02 03:04:05 1996 PST
     | Sat Feb 10 17:32:01 1996 PST
@@ -885,7 +885,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
     AND i.f1 BETWEEN '00:00' AND '23:00'
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
------------------------------+-----------+-----------------------------+-----------------------------
+----------------------------+-----------+----------------------------+----------------------------
  Wed Feb 28 17:32:01 1996   | @ 1 min   | Wed Feb 28 17:33:01 1996   | Wed Feb 28 17:31:01 1996
  Wed Feb 28 17:32:01 1996   | @ 5 hours | Wed Feb 28 22:32:01 1996   | Wed Feb 28 12:32:01 1996
  Thu Feb 29 17:32:01 1996   | @ 1 min   | Thu Feb 29 17:33:01 1996   | Thu Feb 29 17:31:01 1996
@@ -940,12 +940,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
  Mon Feb 10 17:32:01 1997   | @ 5 hours | Mon Feb 10 22:32:01 1997   | Mon Feb 10 12:32:01 1997
  Mon Feb 10 17:32:01 1997   | @ 5 hours | Mon Feb 10 22:32:01 1997   | Mon Feb 10 12:32:01 1997
  Mon Feb 10 17:32:01 1997   | @ 5 hours | Mon Feb 10 22:32:01 1997   | Mon Feb 10 12:32:01 1997
- Mon Feb 10 17:32:01.40 1997 | @ 1 min   | Mon Feb 10 17:33:01.40 1997 | Mon Feb 10 17:31:01.40 1997
- Mon Feb 10 17:32:01.40 1997 | @ 5 hours | Mon Feb 10 22:32:01.40 1997 | Mon Feb 10 12:32:01.40 1997
- Mon Feb 10 17:32:01.50 1997 | @ 1 min   | Mon Feb 10 17:33:01.50 1997 | Mon Feb 10 17:31:01.50 1997
- Mon Feb 10 17:32:01.50 1997 | @ 5 hours | Mon Feb 10 22:32:01.50 1997 | Mon Feb 10 12:32:01.50 1997
- Mon Feb 10 17:32:01.60 1997 | @ 1 min   | Mon Feb 10 17:33:01.60 1997 | Mon Feb 10 17:31:01.60 1997
- Mon Feb 10 17:32:01.60 1997 | @ 5 hours | Mon Feb 10 22:32:01.60 1997 | Mon Feb 10 12:32:01.60 1997
+ Mon Feb 10 17:32:01.4 1997 | @ 1 min   | Mon Feb 10 17:33:01.4 1997 | Mon Feb 10 17:31:01.4 1997
+ Mon Feb 10 17:32:01.4 1997 | @ 5 hours | Mon Feb 10 22:32:01.4 1997 | Mon Feb 10 12:32:01.4 1997
+ Mon Feb 10 17:32:01.5 1997 | @ 1 min   | Mon Feb 10 17:33:01.5 1997 | Mon Feb 10 17:31:01.5 1997
+ Mon Feb 10 17:32:01.5 1997 | @ 5 hours | Mon Feb 10 22:32:01.5 1997 | Mon Feb 10 12:32:01.5 1997
+ Mon Feb 10 17:32:01.6 1997 | @ 1 min   | Mon Feb 10 17:33:01.6 1997 | Mon Feb 10 17:31:01.6 1997
+ Mon Feb 10 17:32:01.6 1997 | @ 5 hours | Mon Feb 10 22:32:01.6 1997 | Mon Feb 10 12:32:01.6 1997
  Mon Feb 10 17:32:02 1997   | @ 1 min   | Mon Feb 10 17:33:02 1997   | Mon Feb 10 17:31:02 1997
  Mon Feb 10 17:32:02 1997   | @ 5 hours | Mon Feb 10 22:32:02 1997   | Mon Feb 10 12:32:02 1997
  Tue Feb 11 17:32:01 1997   | @ 1 min   | Tue Feb 11 17:33:01 1997   | Tue Feb 11 17:31:01 1997
@@ -2182,9 +2182,9 @@ SELECT '' AS "64", d1 AS us_postgres FROM TIMESTAMP_TBL;
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:02 1997
-    | Mon Feb 10 17:32:01.40 1997
-    | Mon Feb 10 17:32:01.50 1997
-    | Mon Feb 10 17:32:01.60 1997
+    | Mon Feb 10 17:32:01.4 1997
+    | Mon Feb 10 17:32:01.5 1997
+    | Mon Feb 10 17:32:01.6 1997
     | Thu Jan 02 00:00:00 1997
     | Thu Jan 02 03:04:05 1997
     | Mon Feb 10 17:32:01 1997
@@ -2265,9 +2265,9 @@ SELECT '' AS "64", d1 AS us_iso FROM TIMESTAMP_TBL;
     | 1997-02-10 17:32:01
     | 1997-02-10 17:32:01
     | 1997-02-10 17:32:02
-    | 1997-02-10 17:32:01.40
-    | 1997-02-10 17:32:01.50
-    | 1997-02-10 17:32:01.60
+    | 1997-02-10 17:32:01.4
+    | 1997-02-10 17:32:01.5
+    | 1997-02-10 17:32:01.6
     | 1997-01-02 00:00:00
     | 1997-01-02 03:04:05
     | 1997-02-10 17:32:01
@@ -2354,9 +2354,9 @@ SELECT '' AS "64", d1 AS us_sql FROM TIMESTAMP_TBL;
     | 02/10/1997 17:32:01
     | 02/10/1997 17:32:01
     | 02/10/1997 17:32:02
-    | 02/10/1997 17:32:01.40
-    | 02/10/1997 17:32:01.50
-    | 02/10/1997 17:32:01.60
+    | 02/10/1997 17:32:01.4
+    | 02/10/1997 17:32:01.5
+    | 02/10/1997 17:32:01.6
     | 01/02/1997 00:00:00
     | 01/02/1997 03:04:05
     | 02/10/1997 17:32:01
@@ -2450,9 +2450,9 @@ SELECT '' AS "65", d1 AS european_postgres FROM TIMESTAMP_TBL;
     | Mon 10 Feb 17:32:01 1997
     | Mon 10 Feb 17:32:01 1997
     | Mon 10 Feb 17:32:02 1997
-    | Mon 10 Feb 17:32:01.40 1997
-    | Mon 10 Feb 17:32:01.50 1997
-    | Mon 10 Feb 17:32:01.60 1997
+    | Mon 10 Feb 17:32:01.4 1997
+    | Mon 10 Feb 17:32:01.5 1997
+    | Mon 10 Feb 17:32:01.6 1997
     | Thu 02 Jan 00:00:00 1997
     | Thu 02 Jan 03:04:05 1997
     | Mon 10 Feb 17:32:01 1997
@@ -2540,9 +2540,9 @@ SELECT '' AS "65", d1 AS european_iso FROM TIMESTAMP_TBL;
     | 1997-02-10 17:32:01
     | 1997-02-10 17:32:01
     | 1997-02-10 17:32:02
-    | 1997-02-10 17:32:01.40
-    | 1997-02-10 17:32:01.50
-    | 1997-02-10 17:32:01.60
+    | 1997-02-10 17:32:01.4
+    | 1997-02-10 17:32:01.5
+    | 1997-02-10 17:32:01.6
     | 1997-01-02 00:00:00
     | 1997-01-02 03:04:05
     | 1997-02-10 17:32:01
@@ -2630,9 +2630,9 @@ SELECT '' AS "65", d1 AS european_sql FROM TIMESTAMP_TBL;
     | 10/02/1997 17:32:01
     | 10/02/1997 17:32:01
     | 10/02/1997 17:32:02
-    | 10/02/1997 17:32:01.40
-    | 10/02/1997 17:32:01.50
-    | 10/02/1997 17:32:01.60
+    | 10/02/1997 17:32:01.4
+    | 10/02/1997 17:32:01.5
+    | 10/02/1997 17:32:01.6
     | 02/01/1997 00:00:00
     | 02/01/1997 03:04:05
     | 10/02/1997 17:32:01

src/test/regress/expected/interval.out

@@ -223,7 +223,7 @@ FROM INTERVAL_MULDIV_TBL;
  1 year 12 days 122:24:00
  -1 years -12 days +93:36:00
  -3 days -14:24:00
- 2 mons 13 days 01:22:28.80
+ 2 mons 13 days 01:22:28.8
  -10 mons +120 days 37:28:21.6567
  1 mon 6 days
  4 mons 6 days
@@ -237,7 +237,7 @@ FROM INTERVAL_MULDIV_TBL;
  28 years 104 days 2961:36:00
  -28 years -104 days +2942:24:00
  -98 days -09:36:00
- 6 years 1 mon -197 days +93:34:27.20
+ 6 years 1 mon -197 days +93:34:27.2
  -24 years -7 mons +3946 days 640:15:11.9498
  2 years 8 mons 24 days
  9 years 6 mons 24 days
@@ -251,7 +251,7 @@ FROM INTERVAL_MULDIV_TBL;
  4 mons 4 days 40:48:00
  -4 mons -4 days +31:12:00
  -1 days -04:48:00
- 25 days -15:32:30.40
+ 25 days -15:32:30.4
  -3 mons +30 days 12:29:27.2189
  12 days
  1 mon 12 days
@@ -656,8 +656,8 @@ select  interval '0'                                AS "zero",
         (interval '1-2' - interval '3 4:05:06.7')   AS "mixed sign",
         (- interval '1-2' + interval '3 4:05:06.7') AS "negative";
  zero | a year 2 months | a bit over a day | a bit over 2 hours |    all fields    |      mixed sign      |      negative      
-------+-----------------+------------------+--------------------+-------------------+-----------------------+---------------------
- PT0S | P1Y2M           | P1DT2H3M4S       | PT2H3M4.45679S     | P1Y2M3DT4H5M6.70S | P1Y2M-3DT-4H-5M-6.70S | P-1Y-2M3DT4H5M6.70S
+------+-----------------+------------------+--------------------+------------------+----------------------+--------------------
+ PT0S | P1Y2M           | P1DT2H3M4S       | PT2H3M4.45679S     | P1Y2M3DT4H5M6.7S | P1Y2M-3DT-4H-5M-6.7S | P-1Y-2M3DT4H5M6.7S
 (1 row)
 
 -- test inputting ISO 8601 4.4.2.1 "Format With Time Unit Designators"
@@ -670,8 +670,8 @@ select  interval 'P0Y'                    AS "zero",
         interval 'P-1Y-2M-3DT-4H-5M-6.7S' AS "negative",
         interval 'PT-0.1S'                AS "fractional second";
  zero | a year 2 months |  a week   | a bit over a day |     all fields     |      negative      | fractional second 
-------+-----------------+-----------+------------------+---------------------+---------------------+-------------------
- 0    | 1-2             | 7 0:00:00 | 1 2:03:04        | +1-2 +3 +4:05:06.70 | -1-2 -3 -4:05:06.70 | -0:00:00.10
+------+-----------------+-----------+------------------+--------------------+--------------------+-------------------
+ 0    | 1-2             | 7 0:00:00 | 1 2:03:04        | +1-2 +3 +4:05:06.7 | -1-2 -3 -4:05:06.7 | -0:00:00.1
 (1 row)
 
 -- test inputting ISO 8601 4.4.2.2 "Alternative Format"
@@ -697,3 +697,23 @@ select  interval 'P0002'                  AS "year only",
  2 years   | 2 years 10 mons | 2 years 10 mons 15 days | 2 years 00:00:01    | 2 years 10 mons 00:00:01 | 2 years 10 mons 15 days 00:00:01 | 10:00:00  | 10:30:00
 (1 row)
 
+-- test a couple rounding cases that changed since 8.3 w/ HAVE_INT64_TIMESTAMP.
+SET IntervalStyle to postgres_verbose;
+select interval '-10 mons -3 days +03:55:06.70';
+                     interval                     
+--------------------------------------------------
+ @ 10 mons 3 days -3 hours -55 mins -6.7 secs ago
+(1 row)
+
+select interval '1 year 2 mons 3 days 04:05:06.699999';
+                      interval                       
+-----------------------------------------------------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6.699999 secs
+(1 row)
+
+select interval '0:0:0.7', interval '@ 0.70 secs', interval '0.7 seconds'; 
+  interval  |  interval  |  interval  
+------------+------------+------------
+ @ 0.7 secs | @ 0.7 secs | @ 0.7 secs
+(1 row)
+

src/test/regress/expected/timestamp.out

@@ -193,9 +193,9 @@ SELECT '' AS "64", d1 FROM TIMESTAMP_TBL;
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:02 1997
-    | Mon Feb 10 17:32:01.40 1997
-    | Mon Feb 10 17:32:01.50 1997
-    | Mon Feb 10 17:32:01.60 1997
+    | Mon Feb 10 17:32:01.4 1997
+    | Mon Feb 10 17:32:01.5 1997
+    | Mon Feb 10 17:32:01.6 1997
     | Thu Jan 02 00:00:00 1997
     | Thu Jan 02 03:04:05 1997
     | Mon Feb 10 17:32:01 1997
@@ -258,14 +258,14 @@ SELECT '' AS "64", d1 FROM TIMESTAMP_TBL;
 SELECT '' AS "48", d1 FROM TIMESTAMP_TBL
    WHERE d1 > timestamp without time zone '1997-01-02';
  48 |             d1             
-----+-----------------------------
+----+----------------------------
     | infinity
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:02 1997
-    | Mon Feb 10 17:32:01.40 1997
-    | Mon Feb 10 17:32:01.50 1997
-    | Mon Feb 10 17:32:01.60 1997
+    | Mon Feb 10 17:32:01.4 1997
+    | Mon Feb 10 17:32:01.5 1997
+    | Mon Feb 10 17:32:01.6 1997
     | Thu Jan 02 03:04:05 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
@@ -348,9 +348,9 @@ SELECT '' AS "63", d1 FROM TIMESTAMP_TBL
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:02 1997
-    | Mon Feb 10 17:32:01.40 1997
-    | Mon Feb 10 17:32:01.50 1997
-    | Mon Feb 10 17:32:01.60 1997
+    | Mon Feb 10 17:32:01.4 1997
+    | Mon Feb 10 17:32:01.5 1997
+    | Mon Feb 10 17:32:01.6 1997
     | Thu Jan 02 03:04:05 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
@@ -433,14 +433,14 @@ SELECT '' AS "16", d1 FROM TIMESTAMP_TBL
 SELECT '' AS "49", d1 FROM TIMESTAMP_TBL
    WHERE d1 >= timestamp without time zone '1997-01-02';
  49 |             d1             
-----+-----------------------------
+----+----------------------------
     | infinity
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:01 1997
     | Mon Feb 10 17:32:02 1997
-    | Mon Feb 10 17:32:01.40 1997
-    | Mon Feb 10 17:32:01.50 1997
-    | Mon Feb 10 17:32:01.60 1997
+    | Mon Feb 10 17:32:01.4 1997
+    | Mon Feb 10 17:32:01.5 1997
+    | Mon Feb 10 17:32:01.6 1997
     | Thu Jan 02 00:00:00 1997
     | Thu Jan 02 03:04:05 1997
     | Mon Feb 10 17:32:01 1997
@@ -494,9 +494,9 @@ SELECT '' AS "54", d1 - timestamp without time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 2 secs
-    | @ 39 days 17 hours 32 mins 1.40 secs
-    | @ 39 days 17 hours 32 mins 1.50 secs
-    | @ 39 days 17 hours 32 mins 1.60 secs
+    | @ 39 days 17 hours 32 mins 1.4 secs
+    | @ 39 days 17 hours 32 mins 1.5 secs
+    | @ 39 days 17 hours 32 mins 1.6 secs
     | @ 0
     | @ 3 hours 4 mins 5 secs
     | @ 39 days 17 hours 32 mins 1 sec
@@ -564,9 +564,9 @@ SELECT '' AS "54", d1 - timestamp without time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 2 secs
-    | @ 39 days 17 hours 32 mins 1.40 secs
-    | @ 39 days 17 hours 32 mins 1.50 secs
-    | @ 39 days 17 hours 32 mins 1.60 secs
+    | @ 39 days 17 hours 32 mins 1.4 secs
+    | @ 39 days 17 hours 32 mins 1.5 secs
+    | @ 39 days 17 hours 32 mins 1.6 secs
     | @ 0
     | @ 3 hours 4 mins 5 secs
     | @ 39 days 17 hours 32 mins 1 sec
@@ -623,14 +623,14 @@ SELECT '' AS "54", d1 as "timestamp",
    date_part( 'minute', d1) AS minute, date_part( 'second', d1) AS second
    FROM TIMESTAMP_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |         timestamp          | year | month | day | hour | minute | second 
-----+-----------------------------+------+-------+-----+------+--------+--------
+----+----------------------------+------+-------+-----+------+--------+--------
     | Thu Jan 01 00:00:00 1970   | 1970 |     1 |   1 |    0 |      0 |      0
     | Mon Feb 10 17:32:01 1997   | 1997 |     2 |  10 |   17 |     32 |      1
     | Mon Feb 10 17:32:01 1997   | 1997 |     2 |  10 |   17 |     32 |      1
     | Mon Feb 10 17:32:02 1997   | 1997 |     2 |  10 |   17 |     32 |      2
-    | Mon Feb 10 17:32:01.40 1997 | 1997 |     2 |  10 |   17 |     32 |    1.4
-    | Mon Feb 10 17:32:01.50 1997 | 1997 |     2 |  10 |   17 |     32 |    1.5
-    | Mon Feb 10 17:32:01.60 1997 | 1997 |     2 |  10 |   17 |     32 |    1.6
+    | Mon Feb 10 17:32:01.4 1997 | 1997 |     2 |  10 |   17 |     32 |    1.4
+    | Mon Feb 10 17:32:01.5 1997 | 1997 |     2 |  10 |   17 |     32 |    1.5
+    | Mon Feb 10 17:32:01.6 1997 | 1997 |     2 |  10 |   17 |     32 |    1.6
     | Thu Jan 02 00:00:00 1997   | 1997 |     1 |   2 |    0 |      0 |      0
     | Thu Jan 02 03:04:05 1997   | 1997 |     1 |   2 |    3 |      4 |      5
     | Mon Feb 10 17:32:01 1997   | 1997 |     2 |  10 |   17 |     32 |      1
@@ -686,14 +686,14 @@ SELECT '' AS "54", d1 as "timestamp",
    date_part( 'usec', d1) AS usec
    FROM TIMESTAMP_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |         timestamp          | quarter | msec  |   usec   
-----+-----------------------------+---------+-------+----------
+----+----------------------------+---------+-------+----------
     | Thu Jan 01 00:00:00 1970   |       1 |     0 |        0
     | Mon Feb 10 17:32:01 1997   |       1 |  1000 |  1000000
     | Mon Feb 10 17:32:01 1997   |       1 |  1000 |  1000000
     | Mon Feb 10 17:32:02 1997   |       1 |  2000 |  2000000
-    | Mon Feb 10 17:32:01.40 1997 |       1 |  1400 |  1400000
-    | Mon Feb 10 17:32:01.50 1997 |       1 |  1500 |  1500000
-    | Mon Feb 10 17:32:01.60 1997 |       1 |  1600 |  1600000
+    | Mon Feb 10 17:32:01.4 1997 |       1 |  1400 |  1400000
+    | Mon Feb 10 17:32:01.5 1997 |       1 |  1500 |  1500000
+    | Mon Feb 10 17:32:01.6 1997 |       1 |  1600 |  1600000
     | Thu Jan 02 00:00:00 1997   |       1 |     0 |        0
     | Thu Jan 02 03:04:05 1997   |       1 |  5000 |  5000000
     | Mon Feb 10 17:32:01 1997   |       1 |  1000 |  1000000
@@ -749,14 +749,14 @@ SELECT '' AS "54", d1 as "timestamp",
    date_part( 'dow', d1) AS dow
    FROM TIMESTAMP_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |         timestamp          | isoyear | week | dow 
-----+-----------------------------+---------+------+-----
+----+----------------------------+---------+------+-----
     | Thu Jan 01 00:00:00 1970   |    1970 |    1 |   4
     | Mon Feb 10 17:32:01 1997   |    1997 |    7 |   1
     | Mon Feb 10 17:32:01 1997   |    1997 |    7 |   1
     | Mon Feb 10 17:32:02 1997   |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.40 1997 |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.50 1997 |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.60 1997 |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.4 1997 |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.5 1997 |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.6 1997 |    1997 |    7 |   1
     | Thu Jan 02 00:00:00 1997   |    1997 |    1 |   4
     | Thu Jan 02 03:04:05 1997   |    1997 |    1 |   4
     | Mon Feb 10 17:32:01 1997   |    1997 |    7 |   1

src/test/regress/expected/timestamptz.out

@@ -264,9 +264,9 @@ SELECT '' AS "64", d1 FROM TIMESTAMPTZ_TBL;
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:02 1997 PST
-    | Mon Feb 10 17:32:01.40 1997 PST
-    | Mon Feb 10 17:32:01.50 1997 PST
-    | Mon Feb 10 17:32:01.60 1997 PST
+    | Mon Feb 10 17:32:01.4 1997 PST
+    | Mon Feb 10 17:32:01.5 1997 PST
+    | Mon Feb 10 17:32:01.6 1997 PST
     | Thu Jan 02 00:00:00 1997 PST
     | Thu Jan 02 03:04:05 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
@@ -330,14 +330,14 @@ SELECT '' AS "64", d1 FROM TIMESTAMPTZ_TBL;
 SELECT '' AS "48", d1 FROM TIMESTAMPTZ_TBL
    WHERE d1 > timestamp with time zone '1997-01-02';
  48 |               d1               
-----+---------------------------------
+----+--------------------------------
     | infinity
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:02 1997 PST
-    | Mon Feb 10 17:32:01.40 1997 PST
-    | Mon Feb 10 17:32:01.50 1997 PST
-    | Mon Feb 10 17:32:01.60 1997 PST
+    | Mon Feb 10 17:32:01.4 1997 PST
+    | Mon Feb 10 17:32:01.5 1997 PST
+    | Mon Feb 10 17:32:01.6 1997 PST
     | Thu Jan 02 03:04:05 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
@@ -421,9 +421,9 @@ SELECT '' AS "63", d1 FROM TIMESTAMPTZ_TBL
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:02 1997 PST
-    | Mon Feb 10 17:32:01.40 1997 PST
-    | Mon Feb 10 17:32:01.50 1997 PST
-    | Mon Feb 10 17:32:01.60 1997 PST
+    | Mon Feb 10 17:32:01.4 1997 PST
+    | Mon Feb 10 17:32:01.5 1997 PST
+    | Mon Feb 10 17:32:01.6 1997 PST
     | Thu Jan 02 03:04:05 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
@@ -507,14 +507,14 @@ SELECT '' AS "16", d1 FROM TIMESTAMPTZ_TBL
 SELECT '' AS "49", d1 FROM TIMESTAMPTZ_TBL
    WHERE d1 >= timestamp with time zone '1997-01-02';
  49 |               d1               
-----+---------------------------------
+----+--------------------------------
     | infinity
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:02 1997 PST
-    | Mon Feb 10 17:32:01.40 1997 PST
-    | Mon Feb 10 17:32:01.50 1997 PST
-    | Mon Feb 10 17:32:01.60 1997 PST
+    | Mon Feb 10 17:32:01.4 1997 PST
+    | Mon Feb 10 17:32:01.5 1997 PST
+    | Mon Feb 10 17:32:01.6 1997 PST
     | Thu Jan 02 00:00:00 1997 PST
     | Thu Jan 02 03:04:05 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
@@ -569,9 +569,9 @@ SELECT '' AS "54", d1 - timestamp with time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 2 secs
-    | @ 39 days 17 hours 32 mins 1.40 secs
-    | @ 39 days 17 hours 32 mins 1.50 secs
-    | @ 39 days 17 hours 32 mins 1.60 secs
+    | @ 39 days 17 hours 32 mins 1.4 secs
+    | @ 39 days 17 hours 32 mins 1.5 secs
+    | @ 39 days 17 hours 32 mins 1.6 secs
     | @ 0
     | @ 3 hours 4 mins 5 secs
     | @ 39 days 17 hours 32 mins 1 sec
@@ -639,9 +639,9 @@ SELECT '' AS "54", d1 - timestamp with time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 2 secs
-    | @ 39 days 17 hours 32 mins 1.40 secs
-    | @ 39 days 17 hours 32 mins 1.50 secs
-    | @ 39 days 17 hours 32 mins 1.60 secs
+    | @ 39 days 17 hours 32 mins 1.4 secs
+    | @ 39 days 17 hours 32 mins 1.5 secs
+    | @ 39 days 17 hours 32 mins 1.6 secs
     | @ 0
     | @ 3 hours 4 mins 5 secs
     | @ 39 days 17 hours 32 mins 1 sec
@@ -699,14 +699,14 @@ SELECT '' AS "54", d1 as timestamptz,
    date_part( 'minute', d1) AS minute, date_part( 'second', d1) AS second
    FROM TIMESTAMPTZ_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |          timestamptz           | year | month | day | hour | minute | second 
-----+---------------------------------+------+-------+-----+------+--------+--------
+----+--------------------------------+------+-------+-----+------+--------+--------
     | Wed Dec 31 16:00:00 1969 PST   | 1969 |    12 |  31 |   16 |      0 |      0
     | Mon Feb 10 17:32:01 1997 PST   | 1997 |     2 |  10 |   17 |     32 |      1
     | Mon Feb 10 17:32:01 1997 PST   | 1997 |     2 |  10 |   17 |     32 |      1
     | Mon Feb 10 17:32:02 1997 PST   | 1997 |     2 |  10 |   17 |     32 |      2
-    | Mon Feb 10 17:32:01.40 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.4
-    | Mon Feb 10 17:32:01.50 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.5
-    | Mon Feb 10 17:32:01.60 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.6
+    | Mon Feb 10 17:32:01.4 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.4
+    | Mon Feb 10 17:32:01.5 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.5
+    | Mon Feb 10 17:32:01.6 1997 PST | 1997 |     2 |  10 |   17 |     32 |    1.6
     | Thu Jan 02 00:00:00 1997 PST   | 1997 |     1 |   2 |    0 |      0 |      0
     | Thu Jan 02 03:04:05 1997 PST   | 1997 |     1 |   2 |    3 |      4 |      5
     | Mon Feb 10 17:32:01 1997 PST   | 1997 |     2 |  10 |   17 |     32 |      1
@@ -763,14 +763,14 @@ SELECT '' AS "54", d1 as timestamptz,
    date_part( 'usec', d1) AS usec
    FROM TIMESTAMPTZ_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |          timestamptz           | quarter | msec  |   usec   
-----+---------------------------------+---------+-------+----------
+----+--------------------------------+---------+-------+----------
     | Wed Dec 31 16:00:00 1969 PST   |       4 |     0 |        0
     | Mon Feb 10 17:32:01 1997 PST   |       1 |  1000 |  1000000
     | Mon Feb 10 17:32:01 1997 PST   |       1 |  1000 |  1000000
     | Mon Feb 10 17:32:02 1997 PST   |       1 |  2000 |  2000000
-    | Mon Feb 10 17:32:01.40 1997 PST |       1 |  1400 |  1400000
-    | Mon Feb 10 17:32:01.50 1997 PST |       1 |  1500 |  1500000
-    | Mon Feb 10 17:32:01.60 1997 PST |       1 |  1600 |  1600000
+    | Mon Feb 10 17:32:01.4 1997 PST |       1 |  1400 |  1400000
+    | Mon Feb 10 17:32:01.5 1997 PST |       1 |  1500 |  1500000
+    | Mon Feb 10 17:32:01.6 1997 PST |       1 |  1600 |  1600000
     | Thu Jan 02 00:00:00 1997 PST   |       1 |     0 |        0
     | Thu Jan 02 03:04:05 1997 PST   |       1 |  5000 |  5000000
     | Mon Feb 10 17:32:01 1997 PST   |       1 |  1000 |  1000000
@@ -827,14 +827,14 @@ SELECT '' AS "54", d1 as timestamptz,
    date_part( 'dow', d1) AS dow
    FROM TIMESTAMPTZ_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
  54 |          timestamptz           | isoyear | week | dow 
-----+---------------------------------+---------+------+-----
+----+--------------------------------+---------+------+-----
     | Wed Dec 31 16:00:00 1969 PST   |    1970 |    1 |   3
     | Mon Feb 10 17:32:01 1997 PST   |    1997 |    7 |   1
     | Mon Feb 10 17:32:01 1997 PST   |    1997 |    7 |   1
     | Mon Feb 10 17:32:02 1997 PST   |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.40 1997 PST |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.50 1997 PST |    1997 |    7 |   1
-    | Mon Feb 10 17:32:01.60 1997 PST |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.4 1997 PST |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.5 1997 PST |    1997 |    7 |   1
+    | Mon Feb 10 17:32:01.6 1997 PST |    1997 |    7 |   1
     | Thu Jan 02 00:00:00 1997 PST   |    1997 |    1 |   4
     | Thu Jan 02 03:04:05 1997 PST   |    1997 |    1 |   4
     | Mon Feb 10 17:32:01 1997 PST   |    1997 |    7 |   1

src/test/regress/sql/interval.sql

@@ -235,3 +235,9 @@ select  interval 'P0002'                  AS "year only",
         interval 'P0002-10-15T1S'         AS "year month day plus time",
         interval 'PT10'                   AS "hour only",
         interval 'PT10:30'                AS "hour minute";
+
+-- test a couple rounding cases that changed since 8.3 w/ HAVE_INT64_TIMESTAMP.
+SET IntervalStyle to postgres_verbose;
+select interval '-10 mons -3 days +03:55:06.70';
+select interval '1 year 2 mons 3 days 04:05:06.699999';
+select interval '0:0:0.7', interval '@ 0.70 secs', interval '0.7 seconds';