Index: src/backend/utils/adt/timestamp.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v
retrieving revision 1.145
diff -c -c -r1.145 timestamp.c
*** src/backend/utils/adt/timestamp.c	23 Jul 2005 14:53:21 -0000	1.145
--- src/backend/utils/adt/timestamp.c	23 Jul 2005 19:34:39 -0000
***************
*** 2294,2300 ****
  {
  	Interval   *span = PG_GETARG_INTERVAL_P(0);
  	float8		factor = PG_GETARG_FLOAT8(1);
! 	double		month_remainder, day_remainder;
  	Interval   *result;
  
  	result = (Interval *) palloc(sizeof(Interval));
--- 2294,2300 ----
  {
  	Interval   *span = PG_GETARG_INTERVAL_P(0);
  	float8		factor = PG_GETARG_FLOAT8(1);
! 	double		month_remainder;
  	Interval   *result;
  
  	result = (Interval *) palloc(sizeof(Interval));
***************
*** 2308,2327 ****
  	result->day = span->day / factor;
  	result->time = span->time / factor;
  
- 	/* Compute remainders */
- 	month_remainder = span->month / factor - result->month;
- 	day_remainder = span->day / factor - result->day;
- 
  	/* Cascade fractions to lower units */
! 	/* fractional months full days into days */
  	result->day += month_remainder * DAYS_PER_MONTH;
- 	/* fractional months partial days into time */
- 	day_remainder += (month_remainder * DAYS_PER_MONTH) - (int)(month_remainder * DAYS_PER_MONTH);
  
  #ifdef HAVE_INT64_TIMESTAMP
! 	result->time += day_remainder * USECS_PER_DAY;
  #else
! 	result->time += day_remainder * SECS_PER_DAY;
  	result->time = JROUND(result->time);
  #endif
  
--- 2308,2327 ----
  	result->day = span->day / factor;
  	result->time = span->time / factor;
  
  	/* Cascade fractions to lower units */
! 	month_remainder = (span->month / factor - result->month);
  	result->day += month_remainder * DAYS_PER_MONTH;
  
+ 	/* fractional months and partial days into time */
  #ifdef HAVE_INT64_TIMESTAMP
! 	/* divide by 'factor' at the end to avoid rounding errors */
! 	result->time += ((span->day - (int)(span->day * factor) +
! 					((span->month - result->month * factor) * DAYS_PER_MONTH))
! 					* USECS_PER_DAY) / factor;
  #else
! 	result->time += (span->day / factor - (int)(span->day / factor) +
! 					month_remainder * DAYS_PER_MONTH -
! 					(int)(month_remainder * DAYS_PER_MONTH)) * SECS_PER_DAY;
  	result->time = JROUND(result->time);
  #endif