Fix xslt_process() to ensure that it inserts a NULL terminator after the

[PostgreSQL.git] / src / test / regress / expected / interval.out

--
-- INTERVAL
--
SET DATESTYLE = 'ISO';
SET IntervalStyle to postgres;
-- check acceptance of "time zone style"
SELECT INTERVAL '01:00' AS "One hour";
 One hour 
----------
 01:00:00
(1 row)

SELECT INTERVAL '+02:00' AS "Two hours";
 Two hours 
-----------
 02:00:00
(1 row)

SELECT INTERVAL '-08:00' AS "Eight hours";
 Eight hours 
-------------
 -08:00:00
(1 row)

SELECT INTERVAL '-1 +02:03' AS "22 hours ago...";
  22 hours ago...  
-------------------
 -1 days +02:03:00
(1 row)

SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
  22 hours ago...  
-------------------
 -1 days +02:03:00
(1 row)

SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 Ten days twelve hours 
-----------------------
 10 days 12:00:00
(1 row)

SELECT INTERVAL '1.5 months' AS "One month 15 days";
 One month 15 days 
-------------------
 1 mon 15 days
(1 row)

SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
            9 years...            
----------------------------------
 9 years 1 mon -12 days +13:14:00
(1 row)

CREATE TABLE INTERVAL_TBL (f1 interval);
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 10 day');
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 34 year');
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 3 months');
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 14 seconds ago');
INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
-- badly formatted interval
INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
ERROR:  invalid input syntax for type interval: "badly formatted interval"
LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted inter...
                                              ^
INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                              ^
-- test interval operators
SELECT '' AS ten, * FROM INTERVAL_TBL;
 ten |       f1        
-----+-----------------
     | 00:01:00
     | 05:00:00
     | 10 days
     | 34 years
     | 3 mons
     | -00:00:14
     | 1 day 02:03:04
     | 6 years
     | 5 mons
     | 5 mons 12:00:00
(10 rows)

SELECT '' AS nine, * FROM INTERVAL_TBL
   WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
 nine |       f1        
------+-----------------
      | 00:01:00
      | 05:00:00
      | 34 years
      | 3 mons
      | -00:00:14
      | 1 day 02:03:04
      | 6 years
      | 5 mons
      | 5 mons 12:00:00
(9 rows)

SELECT '' AS three, * FROM INTERVAL_TBL
   WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
 three |    f1     
-------+-----------
       | 00:01:00
       | 05:00:00
       | -00:00:14
(3 rows)

SELECT '' AS three, * FROM INTERVAL_TBL
   WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
 three |    f1     
-------+-----------
       | 00:01:00
       | 05:00:00
       | -00:00:14
(3 rows)

SELECT '' AS one, * FROM INTERVAL_TBL
   WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
 one |    f1    
-----+----------
     | 34 years
(1 row)

SELECT '' AS five, * FROM INTERVAL_TBL 
   WHERE INTERVAL_TBL.f1 >= interval '@ 1 month';
 five |       f1        
------+-----------------
      | 34 years
      | 3 mons
      | 6 years
      | 5 mons
      | 5 mons 12:00:00
(5 rows)

SELECT '' AS nine, * FROM INTERVAL_TBL
   WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
 nine |       f1        
------+-----------------
      | 00:01:00
      | 05:00:00
      | 10 days
      | 34 years
      | 3 mons
      | 1 day 02:03:04
      | 6 years
      | 5 mons
      | 5 mons 12:00:00
(9 rows)

SELECT '' AS fortyfive, r1.*, r2.*
   FROM INTERVAL_TBL r1, INTERVAL_TBL r2
   WHERE r1.f1 > r2.f1
   ORDER BY r1.f1, r2.f1;
 fortyfive |       f1        |       f1        
-----------+-----------------+-----------------
           | 00:01:00        | -00:00:14
           | 05:00:00        | -00:00:14
           | 05:00:00        | 00:01:00
           | 1 day 02:03:04  | -00:00:14
           | 1 day 02:03:04  | 00:01:00
           | 1 day 02:03:04  | 05:00:00
           | 10 days         | -00:00:14
           | 10 days         | 00:01:00
           | 10 days         | 05:00:00
           | 10 days         | 1 day 02:03:04
           | 3 mons          | -00:00:14
           | 3 mons          | 00:01:00
           | 3 mons          | 05:00:00
           | 3 mons          | 1 day 02:03:04
           | 3 mons          | 10 days
           | 5 mons          | -00:00:14
           | 5 mons          | 00:01:00
           | 5 mons          | 05:00:00
           | 5 mons          | 1 day 02:03:04
           | 5 mons          | 10 days
           | 5 mons          | 3 mons
           | 5 mons 12:00:00 | -00:00:14
           | 5 mons 12:00:00 | 00:01:00
           | 5 mons 12:00:00 | 05:00:00
           | 5 mons 12:00:00 | 1 day 02:03:04
           | 5 mons 12:00:00 | 10 days
           | 5 mons 12:00:00 | 3 mons
           | 5 mons 12:00:00 | 5 mons
           | 6 years         | -00:00:14
           | 6 years         | 00:01:00
           | 6 years         | 05:00:00
           | 6 years         | 1 day 02:03:04
           | 6 years         | 10 days
           | 6 years         | 3 mons
           | 6 years         | 5 mons
           | 6 years         | 5 mons 12:00:00
           | 34 years        | -00:00:14
           | 34 years        | 00:01:00
           | 34 years        | 05:00:00
           | 34 years        | 1 day 02:03:04
           | 34 years        | 10 days
           | 34 years        | 3 mons
           | 34 years        | 5 mons
           | 34 years        | 5 mons 12:00:00
           | 34 years        | 6 years
(45 rows)

-- Test multiplication and division with intervals.
-- Floating point arithmetic rounding errors can lead to unexpected results, 
-- though the code attempts to do the right thing and round up to days and 
-- minutes to avoid results such as '3 days 24:00 hours' or '14:20:60'. 
-- Note that it is expected for some day components to be greater than 29 and 
-- some time components be greater than 23:59:59 due to how intervals are 
-- stored internally.
CREATE TABLE INTERVAL_MULDIV_TBL (span interval);
COPY INTERVAL_MULDIV_TBL FROM STDIN;
SELECT span * 0.3 AS product
FROM INTERVAL_MULDIV_TBL;
              product               
------------------------------------
 1 year 12 days 122:24:00
 -1 years -12 days +93:36:00
 -3 days -14:24:00
 2 mons 13 days 01:22:28.8
 -10 mons +120 days 37:28:21.6567
 1 mon 6 days
 4 mons 6 days
 24 years 11 mons 320 days 16:48:00
(8 rows)

SELECT span * 8.2 AS product
FROM INTERVAL_MULDIV_TBL;
                   product                   
---------------------------------------------
 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 +93:34:27.2
 -24 years -7 mons +3946 days 640:15:11.9498
 2 years 8 mons 24 days
 9 years 6 mons 24 days
 682 years 7 mons 8215 days 19:12:00
(8 rows)

SELECT span / 10 AS quotient
FROM INTERVAL_MULDIV_TBL;
             quotient             
----------------------------------
 4 mons 4 days 40:48:00
 -4 mons -4 days +31:12:00
 -1 days -04:48:00
 25 days -15:32:30.4
 -3 mons +30 days 12:29:27.2189
 12 days
 1 mon 12 days
 8 years 3 mons 126 days 21:36:00
(8 rows)

SELECT span / 100 AS quotient
FROM INTERVAL_MULDIV_TBL;
        quotient         
-------------------------
 12 days 13:40:48
 -12 days -06:28:48
 -02:52:48
 2 days 10:26:44.96
 -6 days +01:14:56.72189
 1 day 04:48:00
 4 days 04:48:00
 9 mons 39 days 16:33:36
(8 rows)

DROP TABLE INTERVAL_MULDIV_TBL;
SET DATESTYLE = 'postgres';
SET IntervalStyle to postgres_verbose;
SELECT '' AS ten, * FROM INTERVAL_TBL;
 ten |              f1               
-----+-------------------------------
     | @ 1 min
     | @ 5 hours
     | @ 10 days
     | @ 34 years
     | @ 3 mons
     | @ 14 secs ago
     | @ 1 day 2 hours 3 mins 4 secs
     | @ 6 years
     | @ 5 mons
     | @ 5 mons 12 hours
(10 rows)

-- test avg(interval), which is somewhat fragile since people have been
-- known to change the allowed input syntax for type interval without
-- updating pg_aggregate.agginitval
select avg(f1) from interval_tbl;
                       avg                       
-------------------------------------------------
 @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
(1 row)

-- test long interval input
select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
                  interval                  
--------------------------------------------
 @ 4541 years 4 mons 4 days 17 mins 31 secs
(1 row)

-- test justify_hours() and justify_days()
SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as "6 mons 5 days 4 hours 3 mins 2 seconds";
 6 mons 5 days 4 hours 3 mins 2 seconds 
----------------------------------------
 @ 6 mons 5 days 4 hours 3 mins 2 secs
(1 row)

SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 7 mons 6 days 5 hours 4 mins 3 seconds 
----------------------------------------
 @ 7 mons 6 days 5 hours 4 mins 3 secs
(1 row)

-- test justify_interval()
SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
  1 month -1 hour   
--------------------
 @ 29 days 23 hours
(1 row)

-- test fractional second input, and detection of duplicate units
SET DATESTYLE = 'ISO';
SET IntervalStyle TO postgres;
SELECT '1 millisecond'::interval, '1 microsecond'::interval,
       '500 seconds 99 milliseconds 51 microseconds'::interval;
   interval   |    interval     |    interval     
--------------+-----------------+-----------------
 00:00:00.001 | 00:00:00.000001 | 00:08:20.099051
(1 row)

SELECT '3 days 5 milliseconds'::interval;
      interval       
---------------------
 3 days 00:00:00.005
(1 row)

SELECT '1 second 2 seconds'::interval;              -- error
ERROR:  invalid input syntax for type interval: "1 second 2 seconds"
LINE 1: SELECT '1 second 2 seconds'::interval;
               ^
SELECT '10 milliseconds 20 milliseconds'::interval; -- error
ERROR:  invalid input syntax for type interval: "10 milliseconds 20 milliseconds"
LINE 1: SELECT '10 milliseconds 20 milliseconds'::interval;
               ^
SELECT '5.5 seconds 3 milliseconds'::interval;      -- error
ERROR:  invalid input syntax for type interval: "5.5 seconds 3 milliseconds"
LINE 1: SELECT '5.5 seconds 3 milliseconds'::interval;
               ^
SELECT '1:20:05 5 microseconds'::interval;          -- error
ERROR:  invalid input syntax for type interval: "1:20:05 5 microseconds"
LINE 1: SELECT '1:20:05 5 microseconds'::interval;
               ^
SELECT '1 day 1 day'::interval;                     -- error
ERROR:  invalid input syntax for type interval: "1 day 1 day"
LINE 1: SELECT '1 day 1 day'::interval;
               ^
SELECT interval '1-2';  -- SQL year-month literal
   interval    
---------------
 1 year 2 mons
(1 row)

SELECT interval '999' second;  -- oversize leading field is ok
 interval 
----------
 00:16:39
(1 row)

SELECT interval '999' minute;
 interval 
----------
 16:39:00
(1 row)

SELECT interval '999' hour;
 interval  
-----------
 999:00:00
(1 row)

SELECT interval '999' day;
 interval 
----------
 999 days
(1 row)

SELECT interval '999' month;
    interval     
-----------------
 83 years 3 mons
(1 row)

-- test SQL-spec syntaxes for restricted field sets
SELECT interval '1' year;
 interval 
----------
 1 year
(1 row)

SELECT interval '2' month;
 interval 
----------
 2 mons
(1 row)

SELECT interval '3' day;
 interval 
----------
 3 days
(1 row)

SELECT interval '4' hour;
 interval 
----------
 04:00:00
(1 row)

SELECT interval '5' minute;
 interval 
----------
 00:05:00
(1 row)

SELECT interval '6' second;
 interval 
----------
 00:00:06
(1 row)

SELECT interval '1' year to month;
 interval 
----------
 1 mon
(1 row)

SELECT interval '1-2' year to month;
   interval    
---------------
 1 year 2 mons
(1 row)

SELECT interval '1 2' day to hour;
    interval    
----------------
 1 day 02:00:00
(1 row)

SELECT interval '1 2:03' day to hour;
    interval    
----------------
 1 day 02:00:00
(1 row)

SELECT interval '1 2:03:04' day to hour;
    interval    
----------------
 1 day 02:00:00
(1 row)

SELECT interval '1 2' day to minute;
ERROR:  invalid input syntax for type interval: "1 2"
LINE 1: SELECT interval '1 2' day to minute;
                        ^
SELECT interval '1 2:03' day to minute;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2:03:04' day to minute;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2' day to second;
ERROR:  invalid input syntax for type interval: "1 2"
LINE 1: SELECT interval '1 2' day to second;
                        ^
SELECT interval '1 2:03' day to second;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2:03:04' day to second;
    interval    
----------------
 1 day 02:03:04
(1 row)

SELECT interval '1 2' hour to minute;
ERROR:  invalid input syntax for type interval: "1 2"
LINE 1: SELECT interval '1 2' hour to minute;
                        ^
SELECT interval '1 2:03' hour to minute;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2:03:04' hour to minute;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2' hour to second;
ERROR:  invalid input syntax for type interval: "1 2"
LINE 1: SELECT interval '1 2' hour to second;
                        ^
SELECT interval '1 2:03' hour to second;
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2:03:04' hour to second;
    interval    
----------------
 1 day 02:03:04
(1 row)

SELECT interval '1 2' minute to second;
ERROR:  invalid input syntax for type interval: "1 2"
LINE 1: SELECT interval '1 2' minute to second;
                        ^
SELECT interval '1 2:03' minute to second;
    interval    
----------------
 1 day 00:02:03
(1 row)

SELECT interval '1 2:03:04' minute to second;
    interval    
----------------
 1 day 02:03:04
(1 row)

SELECT interval '123 11' day to hour; -- ok
     interval      
-------------------
 123 days 11:00:00
(1 row)

SELECT interval '123 11' day; -- not ok
ERROR:  invalid input syntax for type interval: "123 11"
LINE 1: SELECT interval '123 11' day;
                        ^
SELECT interval '123 11'; -- not ok, too ambiguous
ERROR:  invalid input syntax for type interval: "123 11"
LINE 1: SELECT interval '123 11';
                        ^
-- test syntaxes for restricted precision
SELECT interval(0) '1 day 01:23:45.6789';
    interval    
----------------
 1 day 01:23:46
(1 row)

SELECT interval(2) '1 day 01:23:45.6789';
     interval      
-------------------
 1 day 01:23:45.68
(1 row)

SELECT interval '12:34.5678' minute to second(2);  -- per SQL spec
  interval   
-------------
 00:12:34.57
(1 row)

SELECT interval(2) '12:34.5678' minute to second;  -- historical PG
  interval   
-------------
 00:12:34.57
(1 row)

SELECT interval(2) '12:34.5678' minute to second(2);  -- syntax error
ERROR:  interval precision specified twice
LINE 1: SELECT interval(2) '12:34.5678' minute to second(2);
               ^
SELECT interval '1.234' second;
   interval   
--------------
 00:00:01.234
(1 row)

SELECT interval '1.234' second(2);
  interval   
-------------
 00:00:01.23
(1 row)

SELECT interval '1 2.345' day to second(2);
ERROR:  invalid input syntax for type interval: "1 2.345"
LINE 1: SELECT interval '1 2.345' day to second(2);
                        ^
SELECT interval '1 2:03' day to second(2);
    interval    
----------------
 1 day 02:03:00
(1 row)

SELECT interval '1 2:03.4567' day to second(2);
     interval      
-------------------
 1 day 00:02:03.46
(1 row)

SELECT interval '1 2:03:04.5678' day to second(2);
     interval      
-------------------
 1 day 02:03:04.57
(1 row)

SELECT interval '1 2.345' hour to second(2);
ERROR:  invalid input syntax for type interval: "1 2.345"
LINE 1: SELECT interval '1 2.345' hour to second(2);
                        ^
SELECT interval '1 2:03.45678' hour to second(2);
     interval      
-------------------
 1 day 00:02:03.46
(1 row)

SELECT interval '1 2:03:04.5678' hour to second(2);
     interval      
-------------------
 1 day 02:03:04.57
(1 row)

SELECT interval '1 2.3456' minute to second(2);
ERROR:  invalid input syntax for type interval: "1 2.3456"
LINE 1: SELECT interval '1 2.3456' minute to second(2);
                        ^
SELECT interval '1 2:03.5678' minute to second(2);
     interval      
-------------------
 1 day 00:02:03.57
(1 row)

SELECT interval '1 2:03:04.5678' minute to second(2);
     interval      
-------------------
 1 day 02:03:04.57
(1 row)

-- test inputting and outputting SQL standard interval literals
SET IntervalStyle TO sql_standard;
SELECT  interval '0'                       AS "zero",
        interval '1-2' year to month       AS "year-month",
        interval '1 2:03:04' day to second AS "day-time",
        - interval '1-2'                   AS "negative year-month",
        - interval '1 2:03:04'             AS "negative day-time";
 zero | year-month | day-time  | negative year-month | negative day-time 
------+------------+-----------+---------------------+-------------------
 0    | 1-2        | 1 2:03:04 | -1-2                | -1 2:03:04
(1 row)

-- test input of some not-quite-standard interval values in the sql style
SET IntervalStyle TO postgres;
SELECT  interval '+1 -1:00:00',
        interval '-1 +1:00:00',
        interval '+1-2 -3 +4:05:06.789',
        interval '-1-2 +3 -4:05:06.789';
    interval     |     interval      |              interval               |                interval                
-----------------+-------------------+-------------------------------------+----------------------------------------
 1 day -01:00:00 | -1 days +01:00:00 | 1 year 2 mons -3 days +04:05:06.789 | -1 years -2 mons +3 days -04:05:06.789
(1 row)

-- test output of couple non-standard interval values in the sql style
SET IntervalStyle TO sql_standard;
SELECT  interval '1 day -1 hours',
        interval '-1 days +1 hours',
        interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds',
        - interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds';
     interval     |     interval     |       interval       |       ?column?       
------------------+------------------+----------------------+----------------------
 +0-0 +1 -1:00:00 | +0-0 -1 +1:00:00 | +1-2 -3 +4:05:06.789 | -1-2 +3 -4:05:06.789
(1 row)

-- test outputting iso8601 intervals
SET IntervalStyle to iso_8601;
select  interval '0'                                AS "zero",
        interval '1-2'                              AS "a year 2 months",
        interval '1 2:03:04'                        AS "a bit over a day",
        interval '2:03:04.45679'                    AS "a bit over 2 hours",
        (interval '1-2' + interval '3 4:05:06.7')   AS "all fields",
        (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     | P1Y2M3DT4H5M6.7S | 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"
SET IntervalStyle to sql_standard;
select  interval 'P0Y'                    AS "zero",
        interval 'P1Y2M'                  AS "a year 2 months",
        interval 'P1W'                    AS "a week",
        interval 'P1DT2H3M4S'             AS "a bit over a day",
        interval 'P1Y2M3DT4H5M6.7S'       AS "all fields",
        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 +4:05:06.7 | -1-2 -3 -4:05:06.7 | -0:00:00.1
(1 row)

-- test inputting ISO 8601 4.4.2.2 "Alternative Format"
SET IntervalStyle to postgres;
select  interval 'P00021015T103020'       AS "ISO8601 Basic Format",
        interval 'P0002-10-15T10:30:20'   AS "ISO8601 Extended Format";
       ISO8601 Basic Format       |     ISO8601 Extended Format      
----------------------------------+----------------------------------
 2 years 10 mons 15 days 10:30:20 | 2 years 10 mons 15 days 10:30:20
(1 row)

-- Make sure optional ISO8601 alternative format fields are optional.
select  interval 'P0002'                  AS "year only",
        interval 'P0002-10'               AS "year month",
        interval 'P0002-10-15'            AS "year month day",
        interval 'P0002T1S'               AS "year only plus time",
        interval 'P0002-10T1S'            AS "year month plus time",
        interval 'P0002-10-15T1S'         AS "year month day plus time",
        interval 'PT10'                   AS "hour only",
        interval 'PT10:30'                AS "hour minute";
 year only |   year month    |     year month day      | year only plus time |   year month plus time   |     year month day plus time     | hour only | hour minute 
-----------+-----------------+-------------------------+---------------------+--------------------------+----------------------------------+-----------+-------------
 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)

-- check that '30 days' equals '1 month' according to the hash function
select '30 days'::interval = '1 month'::interval as t;
 t 
---
 t
(1 row)

select interval_hash('30 days'::interval) = interval_hash('1 month'::interval) as t;
 t 
---
 t
(1 row)