*** ./src/backend/utils/adt/timestamp.c.orig	Fri Jun  4 15:50:58 2004
--- ./src/backend/utils/adt/timestamp.c	Tue Aug 10 16:31:41 2004
***************
*** 2727,2737 ****
  				fsec = 0;
  				break;
  			case DTK_MILLENNIUM:
! 				tm->tm_year = (tm->tm_year / 1000) * 1000;
  			case DTK_CENTURY:
! 				tm->tm_year = (tm->tm_year / 100) * 100;
  			case DTK_DECADE:
! 				tm->tm_year = (tm->tm_year / 10) * 10;
  			case DTK_YEAR:
  				tm->tm_mon = 1;
  			case DTK_QUARTER:
--- 2727,2752 ----
  				fsec = 0;
  				break;
  			case DTK_MILLENNIUM:
! 				/* see comments in timestamptz_trunc */
! 				if (tm->tm_year > 0)
! 					tm->tm_year = ((tm->tm_year+999) / 1000) * 1000 - 999;
! 				else
! 					tm->tm_year = - ((999 - (tm->tm_year-1))/1000) * 1000 + 1;
  			case DTK_CENTURY:
! 				/* see comments in timestamptz_trunc */
! 				if (tm->tm_year > 0)
! 					tm->tm_year = ((tm->tm_year+99) / 100) * 100 - 99;
! 				else
! 					tm->tm_year = - ((99 - (tm->tm_year-1))/100) * 100 + 1;
  			case DTK_DECADE:
! 				/* see comments in timestamptz_trunc */
! 				if (val != DTK_MILLENNIUM && val != DTK_CENTURY)
! 				{
! 					if (tm->tm_year > 0)
! 						tm->tm_year = (tm->tm_year / 10) * 10;
! 					else
! 						tm->tm_year = - ((8-(tm->tm_year-1)) / 10) * 10;
! 				}
  			case DTK_YEAR:
  				tm->tm_mon = 1;
  			case DTK_QUARTER:
***************
*** 2830,2841 ****
  				tm->tm_sec = 0;
  				fsec = 0;
  				break;
  			case DTK_MILLENNIUM:
! 				tm->tm_year = (tm->tm_year / 1000) * 1000;
  			case DTK_CENTURY:
! 				tm->tm_year = (tm->tm_year / 100) * 100;
  			case DTK_DECADE:
! 				tm->tm_year = (tm->tm_year / 10) * 10;
  			case DTK_YEAR:
  				tm->tm_mon = 1;
  			case DTK_QUARTER:
--- 2845,2877 ----
  				tm->tm_sec = 0;
  				fsec = 0;
  				break;
+ 				/* one may consider DTK_THOUSAND and DTK_HUNDRED... */
  			case DTK_MILLENNIUM:
! 				/* truncating to the millennium? what is this supposed to mean?
! 				 * let us put the first year of the millennium... 
! 				 * i.e. -1000, 1, 1001, 2001...
! 				 */
! 				if (tm->tm_year > 0)
! 					tm->tm_year = ((tm->tm_year+999) / 1000) * 1000 - 999;
! 				else
! 					tm->tm_year = - ((999 - (tm->tm_year-1))/1000) * 1000 + 1;
  			case DTK_CENTURY:
! 				/* truncating to the century? as above: -100, 1, 101... */
! 				if (tm->tm_year > 0)
! 					tm->tm_year = ((tm->tm_year+99) / 100) * 100 - 99 ;
! 				else
! 					tm->tm_year = - ((99 - (tm->tm_year-1))/100) * 100 + 1;
  			case DTK_DECADE:
! 				/* truncating to the decade? first year of the decade.
! 				 * must not be applied if year was truncated before!
! 				 */
! 				if (val != DTK_MILLENNIUM && val != DTK_CENTURY)
! 				{
! 					if (tm->tm_year > 0)
! 						tm->tm_year = (tm->tm_year / 10) * 10;
! 					else
! 						tm->tm_year = - ((8-(tm->tm_year-1)) / 10) * 10;
! 				}
  			case DTK_YEAR:
  				tm->tm_mon = 1;
  			case DTK_QUARTER:
***************
*** 2923,2932 ****
--- 2959,2971 ----
  			switch (val)
  			{
  				case DTK_MILLENNIUM:
+ 					/* caution: C division may have negative remainder */
  					tm->tm_year = (tm->tm_year / 1000) * 1000;
  				case DTK_CENTURY:
+ 					/* caution: C division may have negative remainder */
  					tm->tm_year = (tm->tm_year / 100) * 100;
  				case DTK_DECADE:
+ 					/* caution: C division may have negative remainder */
  					tm->tm_year = (tm->tm_year / 10) * 10;
  				case DTK_YEAR:
  					tm->tm_mon = 0;
***************
*** 3221,3227 ****
  				break;
  
  			case DTK_DECADE:
! 				result = (tm->tm_year / 10);
  				break;
  
  			case DTK_CENTURY:
--- 3260,3273 ----
  				break;
  
  			case DTK_DECADE:
! 				/* what is a decade wrt dates?
! 				 * let us assume that decade 199 is 1990 thru 1999...
! 				 * decade 0 starts on year 1 BC, and -1 is 11 BC thru 2 BC...
! 				 */
! 				if (tm->tm_year>=0)
! 					result = (tm->tm_year / 10);
! 				else
! 					result = -((8-(tm->tm_year-1)) / 10);
  				break;
  
  			case DTK_CENTURY:
***************
*** 3232,3238 ****
  				if (tm->tm_year > 0)
  					result = ((tm->tm_year+99) / 100);
  				else
! 					/* caution: C division may yave negative remainder */
  					result = - ((99 - (tm->tm_year-1))/100);
  				break;
  
--- 3278,3284 ----
  				if (tm->tm_year > 0)
  					result = ((tm->tm_year+99) / 100);
  				else
! 					/* caution: C division may have negative remainder */
  					result = - ((99 - (tm->tm_year-1))/100);
  				break;
  
***************
*** 3445,3459 ****
  				break;
  
  			case DTK_DECADE:
! 				result = (tm->tm_year / 10);
  				break;
  
  			case DTK_CENTURY:
! 				result = (tm->tm_year / 100);
  				break;
  
  			case DTK_MILLENNIUM:
! 				result = (tm->tm_year / 1000);
  				break;
  
  			case DTK_JULIAN:
--- 3491,3517 ----
  				break;
  
  			case DTK_DECADE:
! 				/* see comments in timestamp_part */
! 				if (tm->tm_year>0)
! 					result = (tm->tm_year / 10);
! 				else
! 					result = - ((8-(tm->tm_year-1)) / 10);
  				break;
  
  			case DTK_CENTURY:
! 				/* see comments in timestamp_part */
! 				if (tm->tm_year > 0)
! 					result = ((tm->tm_year+99) / 100);
! 				else
! 					result = - ((99 - (tm->tm_year-1))/100);
  				break;
  
  			case DTK_MILLENNIUM:
! 				/* see comments in timestamp_part */
! 				if (tm->tm_year > 0)
! 					result = ((tm->tm_year+999) / 1000);
! 				else
! 					result = - ((999 - (tm->tm_year-1))/1000);
  				break;
  
  			case DTK_JULIAN:
***************
*** 3606,3619 ****
--- 3664,3680 ----
  					break;
  
  				case DTK_DECADE:
+ 					/* caution: C division may have negative remainder */
  					result = (tm->tm_year / 10);
  					break;
  
  				case DTK_CENTURY:
+ 					/* caution: C division may have negative remainder */
  					result = (tm->tm_year / 100);
  					break;
  
  				case DTK_MILLENNIUM:
+ 					/* caution: C division may have negative remainder */
  					result = (tm->tm_year / 1000);
  					break;
  
*** ./src/test/regress/expected/date.out.orig	Mon Apr 12 14:25:37 2004
--- ./src/test/regress/expected/date.out	Tue Aug 10 16:41:12 2004
***************
*** 930,932 ****
--- 930,1081 ----
           3
  (1 row)
  
+ --
+ -- decade
+ --
+ SELECT EXTRACT(DECADE FROM DATE '1994-12-25');    -- 199
+  date_part 
+ -----------
+        199
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0010-01-01');    --   1
+  date_part 
+ -----------
+          1
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0009-12-31');    --   0
+  date_part 
+ -----------
+          0
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0001-01-01 BC'); --   0
+  date_part 
+ -----------
+          0
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0002-12-31 BC'); --  -1
+  date_part 
+ -----------
+         -1
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0011-01-01 BC'); --  -1
+  date_part 
+ -----------
+         -1
+ (1 row)
+ 
+ SELECT EXTRACT(DECADE FROM DATE '0012-12-31 BC'); --  -2
+  date_part 
+ -----------
+         -2
+ (1 row)
+ 
+ --
+ -- some other types:
+ --
+ -- on a timestamp.
+ SELECT EXTRACT(CENTURY FROM NOW())>=21 AS True;       -- true
+  true 
+ ------
+  t
+ (1 row)
+ 
+ SELECT EXTRACT(CENTURY FROM TIMESTAMP '1970-03-20 04:30:00.00000'); -- 20
+  date_part 
+ -----------
+         20
+ (1 row)
+ 
+ -- on an interval
+ SELECT EXTRACT(CENTURY FROM INTERVAL '100 y');  -- 1
+  date_part 
+ -----------
+          1
+ (1 row)
+ 
+ SELECT EXTRACT(CENTURY FROM INTERVAL '99 y');   -- 0
+  date_part 
+ -----------
+          0
+ (1 row)
+ 
+ SELECT EXTRACT(CENTURY FROM INTERVAL '-99 y');  -- 0
+  date_part 
+ -----------
+          0
+ (1 row)
+ 
+ SELECT EXTRACT(CENTURY FROM INTERVAL '-100 y'); -- -1
+  date_part 
+ -----------
+         -1
+ (1 row)
+ 
+ --
+ -- test trunc function!
+ --
+ SELECT DATE_TRUNC('MILLENNIUM', TIMESTAMP '1970-03-20 04:30:00.00000'); -- 1001
+         date_trunc        
+ --------------------------
+  Thu Jan 01 00:00:00 1001
+ (1 row)
+ 
+ SELECT DATE_TRUNC('MILLENNIUM', DATE '1970-03-20'); -- 1001-01-01
+           date_trunc          
+ ------------------------------
+  Thu Jan 01 00:00:00 1001 PST
+ (1 row)
+ 
+ SELECT DATE_TRUNC('CENTURY', TIMESTAMP '1970-03-20 04:30:00.00000'); -- 1901
+         date_trunc        
+ --------------------------
+  Tue Jan 01 00:00:00 1901
+ (1 row)
+ 
+ SELECT DATE_TRUNC('CENTURY', DATE '1970-03-20'); -- 1901
+           date_trunc          
+ ------------------------------
+  Tue Jan 01 00:00:00 1901 PST
+ (1 row)
+ 
+ SELECT DATE_TRUNC('CENTURY', DATE '2004-08-10'); -- 2001-01-01
+           date_trunc          
+ ------------------------------
+  Mon Jan 01 00:00:00 2001 PST
+ (1 row)
+ 
+ SELECT DATE_TRUNC('CENTURY', DATE '0002-02-04'); -- 0001-01-01
+           date_trunc          
+ ------------------------------
+  Mon Jan 01 00:00:00 0001 PST
+ (1 row)
+ 
+ SELECT DATE_TRUNC('CENTURY', DATE '0055-08-10 BC'); -- 0100-01-01 BC
+            date_trunc            
+ ---------------------------------
+  Tue Jan 01 00:00:00 0100 PST BC
+ (1 row)
+ 
+ SELECT DATE_TRUNC('DECADE', DATE '1993-12-25'); -- 1990-01-01
+           date_trunc          
+ ------------------------------
+  Mon Jan 01 00:00:00 1990 PST
+ (1 row)
+ 
+ SELECT DATE_TRUNC('DECADE', DATE '0004-12-25'); -- 0001-01-01 BC
+            date_trunc            
+ ---------------------------------
+  Sat Jan 01 00:00:00 0001 PST BC
+ (1 row)
+ 
+ SELECT DATE_TRUNC('DECADE', DATE '0002-12-31 BC'); -- 0011-01-01 BC
+            date_trunc            
+ ---------------------------------
+  Mon Jan 01 00:00:00 0011 PST BC
+ (1 row)
+ 
*** ./src/test/regress/sql/date.sql.orig	Mon Apr 12 14:25:37 2004
--- ./src/test/regress/sql/date.sql	Tue Aug 10 16:40:13 2004
***************
*** 235,237 ****
--- 235,271 ----
  SELECT EXTRACT(MILLENNIUM FROM DATE '2001-01-01');    --  3
  -- next test to be fixed on the turn of the next millennium;-)
  SELECT EXTRACT(MILLENNIUM FROM CURRENT_DATE);         --  3
+ --
+ -- decade
+ --
+ SELECT EXTRACT(DECADE FROM DATE '1994-12-25');    -- 199
+ SELECT EXTRACT(DECADE FROM DATE '0010-01-01');    --   1
+ SELECT EXTRACT(DECADE FROM DATE '0009-12-31');    --   0
+ SELECT EXTRACT(DECADE FROM DATE '0001-01-01 BC'); --   0
+ SELECT EXTRACT(DECADE FROM DATE '0002-12-31 BC'); --  -1
+ SELECT EXTRACT(DECADE FROM DATE '0011-01-01 BC'); --  -1
+ SELECT EXTRACT(DECADE FROM DATE '0012-12-31 BC'); --  -2
+ --
+ -- some other types:
+ --
+ -- on a timestamp.
+ SELECT EXTRACT(CENTURY FROM NOW())>=21 AS True;       -- true
+ SELECT EXTRACT(CENTURY FROM TIMESTAMP '1970-03-20 04:30:00.00000'); -- 20
+ -- on an interval
+ SELECT EXTRACT(CENTURY FROM INTERVAL '100 y');  -- 1
+ SELECT EXTRACT(CENTURY FROM INTERVAL '99 y');   -- 0
+ SELECT EXTRACT(CENTURY FROM INTERVAL '-99 y');  -- 0
+ SELECT EXTRACT(CENTURY FROM INTERVAL '-100 y'); -- -1
+ --
+ -- test trunc function!
+ --
+ SELECT DATE_TRUNC('MILLENNIUM', TIMESTAMP '1970-03-20 04:30:00.00000'); -- 1001
+ SELECT DATE_TRUNC('MILLENNIUM', DATE '1970-03-20'); -- 1001-01-01
+ SELECT DATE_TRUNC('CENTURY', TIMESTAMP '1970-03-20 04:30:00.00000'); -- 1901
+ SELECT DATE_TRUNC('CENTURY', DATE '1970-03-20'); -- 1901
+ SELECT DATE_TRUNC('CENTURY', DATE '2004-08-10'); -- 2001-01-01
+ SELECT DATE_TRUNC('CENTURY', DATE '0002-02-04'); -- 0001-01-01
+ SELECT DATE_TRUNC('CENTURY', DATE '0055-08-10 BC'); -- 0100-01-01 BC
+ SELECT DATE_TRUNC('DECADE', DATE '1993-12-25'); -- 1990-01-01
+ SELECT DATE_TRUNC('DECADE', DATE '0004-12-25'); -- 0001-01-01 BC
+ SELECT DATE_TRUNC('DECADE', DATE '0002-12-31 BC'); -- 0011-01-01 BC