*** a/src/backend/utils/adt/datetime.c
--- b/src/backend/utils/adt/datetime.c
***************
*** 406,421 **** static void
  TrimTrailingZeros(char *str)
  {
  	int			len = strlen(str);
- 
- #if 0
- 	/* chop off trailing one to cope with interval rounding */
- 	if (strcmp(str + len - 4, "0001") == 0)
- 	{
- 		len -= 4;
- 		*(str + len) = '\0';
- 	}
- #endif
- 
  	/* chop off trailing zeros... but leave at least 2 fractional digits */
  	while (*(str + len - 1) == '0' && *(str + len - 3) != '.')
  	{
--- 406,411 ----
***************
*** 2724,2732 **** DecodeSpecial(int field, char *lowtoken, int *val)
  
  
  /*
!  * A small helper function to avoid cut&paste code in DecodeIso8601Interval
   */
! static void adjust_fval(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
  {
  	int	sec;
  	if (fval == 0) return;
--- 2714,2723 ----
  
  
  /*
!  * Small helper functions to avoid cut&paste code in DecodeInterval and DecodeIso8601Interval
   */
! static void 
! adjust_fractional_seconds(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
  {
  	int	sec;
  	if (fval == 0) return;
***************
*** 2734,2745 **** static void adjust_fval(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
  	sec		    = fval;
  	tm->tm_sec += sec;
  #ifdef HAVE_INT64_TIMESTAMP
! 	*fsec	   += ((fval - sec) * 1000000);
  #else
  	*fsec	   += (fval - sec);
  #endif
  }
  
  
  /* DecodeISO8601Interval()
   *
--- 2725,2748 ----
  	sec		    = fval;
  	tm->tm_sec += sec;
  #ifdef HAVE_INT64_TIMESTAMP
! 	*fsec	   += rint((fval - sec) * 1000000);
  #else
  	*fsec	   += (fval - sec);
  #endif
  }
  
+ static void 
+ adjust_fractional_days(double fval,struct pg_tm * tm, fsec_t *fsec, int scale)
+ {
+ 	int	extra_days;
+ 	if (fval == 0) return;
+ 	fval *= scale;
+ 	extra_days = fval;
+ 	tm->tm_mday += extra_days;
+ 	fval -= extra_days;
+ 	adjust_fractional_seconds(fval,tm,fsec, SECS_PER_DAY);
+ }
+ 
  
  /* DecodeISO8601Interval()
   *
***************
*** 2768,2775 **** int
  DecodeISO8601Interval(char *str, struct pg_tm * tm, fsec_t *fsec) 
  {
  	char    unit;
- 	int		fmask = 0,
- 			tmask;
  	int		val;
  	double	fval;
  	int		datepart = true;
--- 2771,2776 ----
***************
*** 2785,2798 **** DecodeISO8601Interval(char *str, struct pg_tm * tm, fsec_t *fsec)
  
  	/*
  	 * An ISO 8601 "time-interval by duration only" must start
! 	 * with a 'P'.  If it contains a date-part, 'p' will be the
! 	 * only character in the field.  If it contains no date part
! 	 * it will contain exactly to characters 'PT' indicating a
! 	 * time part.
! 	 * Anything else does not match an ISO 8601 basic interval
! 	 * and will be treated like a traditional postgresql interval.
  	 */
! 	if (!(str[0] == 'P'))
  	{
  		return DTERR_BAD_FORMAT;
  	}
--- 2786,2795 ----
  
  	/*
  	 * An ISO 8601 "time-interval by duration only" must start
! 	 * with a 'P' and needs to be at least 3 characters long to
! 	 * insure that it had a field set.
  	 */
! 	if (strlen(str)<3 || !(str[0] == 'P'))
  	{
  		return DTERR_BAD_FORMAT;
  	}
***************
*** 2826,2860 **** DecodeISO8601Interval(char *str, struct pg_tm * tm, fsec_t *fsec)
  			{
  				case 'D':
  					tm->tm_mday += val;
! 					adjust_fval(fval,tm,fsec, 86400);
! 					tmask = ((fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY));
  					break;
- 
  				case 'W':
  					tm->tm_mday += val * 7;
! 					adjust_fval(fval,tm,fsec,7 * 86400);
! 					tmask = ((fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY));
  					break;
- 
  				case 'M':
  					tm->tm_mon += val;
! 					adjust_fval(fval,tm,fsec,30 * 86400);
! 					tmask = DTK_M(MONTH);
  					break;
- 
  				case 'Y':
- 					/*
- 					 * Why can fractional months produce seconds,
- 					 * but fractional years can't?  Well the older
- 					 * interval code below has the same property
- 					 * so this one follows the other one too.
- 					 */
  					tm->tm_year += val;
  					if (fval != 0)
  						tm->tm_mon += (fval * 12);
- 					tmask = ((fmask & DTK_M(YEAR)) ? 0 : DTK_M(YEAR));
  					break;
- 
  				default:
  					return DTERR_BAD_FORMAT;  /* not a vald ISO8601 date unit prefix */
  			}
--- 2823,2843 ----
  			{
  				case 'D':
  					tm->tm_mday += val;
! 					adjust_fractional_seconds(fval,tm,fsec, SECS_PER_DAY);
  					break;
  				case 'W':
  					tm->tm_mday += val * 7;
! 					adjust_fractional_days(fval,tm,fsec,7);
  					break;
  				case 'M':
  					tm->tm_mon += val;
! 					adjust_fractional_days(fval,tm,fsec,DAYS_PER_MONTH);
  					break;
  				case 'Y':
  					tm->tm_year += val;
  					if (fval != 0)
  						tm->tm_mon += (fval * 12);
  					break;
  				default:
  					return DTERR_BAD_FORMAT;  /* not a vald ISO8601 date unit prefix */
  			}
***************
*** 2865,2902 **** DecodeISO8601Interval(char *str, struct pg_tm * tm, fsec_t *fsec)
  			{
  				case 'S':
  					tm->tm_sec += val;
! 					adjust_fval(fval,tm,fsec,1);
! 					tmask = DTK_M(SECOND);
  					break;
  				case 'M':
  					tm->tm_min += val;
! 					adjust_fval(fval,tm,fsec,60);
! 					tmask = DTK_M(MINUTE);
  					break;
  				case 'H':
  					tm->tm_hour += val;
! 					adjust_fval(fval,tm,fsec,3600);
! 					tmask = DTK_M(HOUR);
  					break;
  				default:
  					return DTERR_BAD_FORMAT;  /* not a vald ISO8601 time unit prefix */
  			}
  		}
- 		fmask |= tmask;
  	}
  
! 	if (*fsec != 0)
! 	{
! 		int			sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 		sec = (*fsec / INT64CONST(1000000));
! 		*fsec -= (sec * INT64CONST(1000000));
! #else
! 		TMODULO(*fsec, sec, 1e0);
! #endif
! 		tm->tm_sec += sec;
! 	}
! 	return (fmask != 0) ? 0 : -1;
  }
  
  
--- 2848,2870 ----
  			{
  				case 'S':
  					tm->tm_sec += val;
! 					adjust_fractional_seconds(fval,tm,fsec,1);
  					break;
  				case 'M':
  					tm->tm_min += val;
! 					adjust_fractional_seconds(fval,tm,fsec,SECS_PER_MINUTE);
  					break;
  				case 'H':
  					tm->tm_hour += val;
! 					adjust_fractional_seconds(fval,tm,fsec,SECS_PER_HOUR);
  					break;
  				default:
  					return DTERR_BAD_FORMAT;  /* not a vald ISO8601 time unit prefix */
  			}
  		}
  	}
  
! 	return 0;
  }
  
  
***************
*** 3069,3099 **** DecodeInterval(char **field, int *ftype, int nf, int range,
  				switch (type)
  				{
  					case DTK_MICROSEC:
! #ifdef HAVE_INT64_TIMESTAMP
! 						*fsec += rint(val + fval);
! #else
! 						*fsec += (val + fval) * 1e-6;
! #endif
  						tmask = DTK_M(MICROSECOND);
  						break;
  
  					case DTK_MILLISEC:
! #ifdef HAVE_INT64_TIMESTAMP
! 						*fsec += rint((val + fval) * 1000);
! #else
! 						*fsec += (val + fval) * 1e-3;
! #endif
  						tmask = DTK_M(MILLISECOND);
  						break;
  
  					case DTK_SECOND:
  						tm->tm_sec += val;
! #ifdef HAVE_INT64_TIMESTAMP
! 						*fsec += rint(fval * 1000000);
! #else
! 						*fsec += fval;
! #endif
! 
  						/*
  						 * If any subseconds were specified, consider this
  						 * microsecond and millisecond input as well.
--- 3037,3054 ----
  				switch (type)
  				{
  					case DTK_MICROSEC:
! 						adjust_fractional_seconds((val + fval) * 1e-6,tm,fsec,1);
  						tmask = DTK_M(MICROSECOND);
  						break;
  
  					case DTK_MILLISEC:
! 						adjust_fractional_seconds((val + fval) * 1e-3,tm,fsec,1);
  						tmask = DTK_M(MILLISECOND);
  						break;
  
  					case DTK_SECOND:
  						tm->tm_sec += val;
! 						adjust_fractional_seconds(fval,tm,fsec,1);
  						/*
  						 * If any subseconds were specified, consider this
  						 * microsecond and millisecond input as well.
***************
*** 3106,3215 **** DecodeInterval(char **field, int *ftype, int nf, int range,
  
  					case DTK_MINUTE:
  						tm->tm_min += val;
! 						if (fval != 0)
! 						{
! 							int			sec;
! 
! 							fval *= SECS_PER_MINUTE;
! 							sec = fval;
! 							tm->tm_sec += sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 							*fsec += rint((fval - sec) * 1000000);
! #else
! 							*fsec += fval - sec;
! #endif
! 						}
  						tmask = DTK_M(MINUTE);
  						break;
  
  					case DTK_HOUR:
  						tm->tm_hour += val;
! 						if (fval != 0)
! 						{
! 							int			sec;
! 
! 							fval *= SECS_PER_HOUR;
! 							sec = fval;
! 							tm->tm_sec += sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 							*fsec += rint((fval - sec) * 1000000);
! #else
! 							*fsec += fval - sec;
! #endif
! 						}
  						tmask = DTK_M(HOUR);
  						type = DTK_DAY;
  						break;
  
  					case DTK_DAY:
  						tm->tm_mday += val;
! 						if (fval != 0)
! 						{
! 							int			sec;
! 
! 							fval *= SECS_PER_DAY;
! 							sec = fval;
! 							tm->tm_sec += sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 							*fsec += rint((fval - sec) * 1000000);
! #else
! 							*fsec += fval - sec;
! #endif
! 						}
  						tmask = (fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY);
  						break;
  
  					case DTK_WEEK:
  						tm->tm_mday += val * 7;
! 						if (fval != 0)
! 						{
! 							int			extra_days;
! 
! 							fval *= 7;
! 							extra_days = (int32) fval;
! 							tm->tm_mday += extra_days;
! 							fval -= extra_days;
! 							if (fval != 0)
! 							{
! 								int			sec;
! 
! 								fval *= SECS_PER_DAY;
! 								sec = fval;
! 								tm->tm_sec += sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 								*fsec += rint((fval - sec) * 1000000);
! #else
! 								*fsec += fval - sec;
! #endif
! 							}
! 						}
  						tmask = (fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY);
  						break;
  
  					case DTK_MONTH:
  						tm->tm_mon += val;
! 						if (fval != 0)
! 						{
! 							int			day;
! 
! 							fval *= DAYS_PER_MONTH;
! 							day = fval;
! 							tm->tm_mday += day;
! 							fval -= day;
! 							if (fval != 0)
! 							{
! 								int			sec;
! 
! 								fval *= SECS_PER_DAY;
! 								sec = fval;
! 								tm->tm_sec += sec;
! #ifdef HAVE_INT64_TIMESTAMP
! 								*fsec += rint((fval - sec) * 1000000);
! #else
! 								*fsec += fval - sec;
! #endif
! 							}
! 						}
  						tmask = DTK_M(MONTH);
  						break;
  
--- 3061,3092 ----
  
  					case DTK_MINUTE:
  						tm->tm_min += val;
! 						adjust_fractional_seconds(fval,tm,fsec, SECS_PER_MINUTE);
  						tmask = DTK_M(MINUTE);
  						break;
  
  					case DTK_HOUR:
  						tm->tm_hour += val;
! 						adjust_fractional_seconds(fval,tm,fsec, SECS_PER_HOUR);
  						tmask = DTK_M(HOUR);
  						type = DTK_DAY;
  						break;
  
  					case DTK_DAY:
  						tm->tm_mday += val;
! 						adjust_fractional_seconds(fval,tm,fsec, SECS_PER_DAY);
  						tmask = (fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY);
  						break;
  
  					case DTK_WEEK:
  						tm->tm_mday += val * 7;
! 						adjust_fractional_days(fval,tm,fsec,7);
  						tmask = (fmask & DTK_M(DAY)) ? 0 : DTK_M(DAY);
  						break;
  
  					case DTK_MONTH:
  						tm->tm_mon += val;
! 						adjust_fractional_days(fval,tm,fsec,DAYS_PER_MONTH);
  						tmask = DTK_M(MONTH);
  						break;
  
***************
*** 3283,3301 **** DecodeInterval(char **field, int *ftype, int nf, int range,
  		fmask |= tmask;
  	}
  
- 	if (*fsec != 0)
- 	{
- 		int			sec;
- 
- #ifdef HAVE_INT64_TIMESTAMP
- 		sec = *fsec / USECS_PER_SEC;
- 		*fsec -= sec * USECS_PER_SEC;
- #else
- 		TMODULO(*fsec, sec, 1.0);
- #endif
- 		tm->tm_sec += sec;
- 	}
- 
  	if (is_before)
  	{
  		*fsec = -(*fsec);
--- 3160,3165 ----
***************
*** 3810,3815 **** AppendFsec(char * cp,fsec_t fsec)
--- 3674,3710 ----
      TrimTrailingZeros(cp);
  }
  
+ static char * 
+ AddVerboseIntervalPart(char * cp, int value, char *units,
+                                       bool * is_zero, bool *is_before)
+ {
+     if (value==0) return cp;
+ 	cp += sprintf(cp," ");
+     if (*is_zero)
+ 	    *is_before = (value < 0);
+ 	*is_zero = FALSE;
+ 	if ( (value < 0) ^ (*is_before) )
+ 		cp += sprintf(cp,"-");
+     value = abs(value);
+ 	cp += sprintf(cp,"%d %s%s",value,units,(value == 1) ? "" : "s");
+     return cp;
+ }
+ 
+ static char * 
+ AddPostgresIntervalPart(char * cp, int value, char *units,
+                             bool * is_zero, bool *is_before)
+ {
+     if (value==0) return cp;
+ 	cp += sprintf(cp, "%s%s%d %s%s",
+ 				  (!*is_zero) ? " " : "",
+ 				  (*is_before && value > 0) ? "+" : "",
+ 				  value, 
+ 				  units,
+ 				  (value != 1) ? "s" : "");
+ 	*is_before = (value < 0);
+ 	*is_zero = FALSE;
+     return cp;
+ }
  
  /* EncodeInterval()
   * Interpret time structure as a delta time and convert to string.
***************
*** 3834,3840 **** int
  EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
  {
  	bool		is_before = FALSE;
! 	bool		is_nonzero = FALSE;
  	char	   *cp = str;
  
      /*
--- 3729,3735 ----
  EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
  {
  	bool		is_before = FALSE;
! 	bool		is_zero = TRUE;
  	char	   *cp = str;
  
      /*
***************
*** 3848,3858 **** EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
      int min   = tm->tm_min;
      int sec   = tm->tm_sec;
  
- 	/*
- 	 * The sign of year and month are guaranteed to match, since they are
- 	 * stored internally as "month". But we'll need to check for is_before and
- 	 * is_nonzero when determining the signs of hour/minute/seconds fields.
- 	 */
  	switch (style)
  	{
  	    /* SQL Standard interval literals */
--- 3743,3748 ----
***************
*** 3955,4167 **** EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
  
  		/* compatible with postgresql 8.3 when DateStyle = 'iso' */
  		case INTSTYLE_POSTGRES:
! 			if (tm->tm_year != 0)
! 			{
! 				sprintf(cp, "%d year%s",
! 						tm->tm_year, (tm->tm_year != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				is_before = (tm->tm_year < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (tm->tm_mon != 0)
! 			{
! 				sprintf(cp, "%s%s%d mon%s", is_nonzero ? " " : "",
! 						(is_before && tm->tm_mon > 0) ? "+" : "",
! 						tm->tm_mon, (tm->tm_mon != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				is_before = (tm->tm_mon < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (tm->tm_mday != 0)
! 			{
! 				sprintf(cp, "%s%s%d day%s", is_nonzero ? " " : "",
! 						(is_before && tm->tm_mday > 0) ? "+" : "",
! 						tm->tm_mday, (tm->tm_mday != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				is_before = (tm->tm_mday < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (!is_nonzero || tm->tm_hour != 0 || tm->tm_min != 0 ||
! 				tm->tm_sec != 0 || fsec != 0)
  			{
! 				int			minus = (tm->tm_hour < 0 || tm->tm_min < 0 ||
! 									 tm->tm_sec < 0 || fsec < 0);
! 
! 				sprintf(cp, "%s%s%02d:%02d", is_nonzero ? " " : "",
  						(minus ? "-" : (is_before ? "+" : "")),
! 						abs(tm->tm_hour), abs(tm->tm_min));
! 				cp += strlen(cp);
! 				/* Mark as "non-zero" since the fields are now filled in */
! 				is_nonzero = TRUE;
! 
! 				/* need fractional seconds? */
! 				if (fsec != 0)
! 				{
! #ifdef HAVE_INT64_TIMESTAMP
! 					sprintf(cp, ":%02d", abs(tm->tm_sec));
! 					cp += strlen(cp);
! 					sprintf(cp, ".%06d", Abs(fsec));
! #else
! 					fsec += tm->tm_sec;
! 					sprintf(cp, ":%012.9f", fabs(fsec));
! #endif
! 					TrimTrailingZeros(cp);
! 					cp += strlen(cp);
! 				}
! 				else
! 				{
! 					sprintf(cp, ":%02d", abs(tm->tm_sec));
! 					cp += strlen(cp);
! 				}
! 			}
! 			if (!is_nonzero)
! 			{
! 				strcat(cp, "0");
! 				cp += strlen(cp);
  			}
  			break;
  
  		/* compatible with postgresql 8.3 when DateStyle = 'sql' */
  		case INTSTYLE_POSTGRES_VERBOSE:
  		default:
! 			strcpy(cp, "@ ");
! 			cp += strlen(cp);
! 
! 			if (tm->tm_year != 0)
! 			{
! 				int			year = tm->tm_year;
! 
! 				if (tm->tm_year < 0)
! 					year = -year;
! 
! 				sprintf(cp, "%d year%s", year,
! 						(year != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				is_before = (tm->tm_year < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (tm->tm_mon != 0)
! 			{
! 				int			mon = tm->tm_mon;
! 
! 				if (is_before || (!is_nonzero && tm->tm_mon < 0))
! 					mon = -mon;
! 
! 				sprintf(cp, "%s%d mon%s", is_nonzero ? " " : "", mon,
! 						(mon != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (tm->tm_mon < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (tm->tm_mday != 0)
! 			{
! 				int			day = tm->tm_mday;
! 
! 				if (is_before || (!is_nonzero && tm->tm_mday < 0))
! 					day = -day;
! 
! 				sprintf(cp, "%s%d day%s", is_nonzero ? " " : "", day,
! 						(day != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (tm->tm_mday < 0);
! 				is_nonzero = TRUE;
! 			}
! 			if (tm->tm_hour != 0)
! 			{
! 				int			hour = tm->tm_hour;
! 
! 				if (is_before || (!is_nonzero && tm->tm_hour < 0))
! 					hour = -hour;
! 
! 				sprintf(cp, "%s%d hour%s", is_nonzero ? " " : "", hour,
! 						(hour != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (tm->tm_hour < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			if (tm->tm_min != 0)
! 			{
! 				int			min = tm->tm_min;
! 
! 				if (is_before || (!is_nonzero && tm->tm_min < 0))
! 					min = -min;
! 
! 				sprintf(cp, "%s%d min%s", is_nonzero ? " " : "", min,
! 						(min != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (tm->tm_min < 0);
! 				is_nonzero = TRUE;
! 			}
! 
! 			/* fractional seconds? */
! 			if (fsec != 0)
! 			{
! 				fsec_t		sec;
! 
! #ifdef HAVE_INT64_TIMESTAMP
! 				sec = fsec;
! 				if (is_before || (!is_nonzero && tm->tm_sec < 0))
! 				{
! 					tm->tm_sec = -tm->tm_sec;
! 					sec = -sec;
! 					is_before = TRUE;
! 				}
! 				else if (!is_nonzero && tm->tm_sec == 0 && fsec < 0)
! 				{
! 					sec = -sec;
! 					is_before = TRUE;
! 				}
! 				sprintf(cp, "%s%d.%02d secs", is_nonzero ? " " : "",
! 						tm->tm_sec, abs((int) rint(sec / 10000.0)));
! 				cp += strlen(cp);
! #else
! 				fsec += tm->tm_sec;
! 				sec = fsec;
! 				if (is_before || (!is_nonzero && fsec < 0))
! 					sec = -sec;
! 
! 				sprintf(cp, "%s%.2f secs", is_nonzero ? " " : "", sec);
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (fsec < 0);
! #endif
! 				is_nonzero = TRUE;
! 			}
! 			/* otherwise, integer seconds only? */
! 			else if (tm->tm_sec != 0)
! 			{
! 				int			sec = tm->tm_sec;
! 
! 				if (is_before || (!is_nonzero && tm->tm_sec < 0))
! 					sec = -sec;
! 
! 				sprintf(cp, "%s%d sec%s", is_nonzero ? " " : "", sec,
! 						(sec != 1) ? "s" : "");
! 				cp += strlen(cp);
! 				if (!is_nonzero)
! 					is_before = (tm->tm_sec < 0);
! 				is_nonzero = TRUE;
! 			}
! 			if (!is_nonzero)
  			{
! 				strcat(cp, "0");
  				cp += strlen(cp);
  			}
  			if (is_before)
- 			{
  				strcat(cp, " ago");
- 				cp += strlen(cp);
- 			}
  			break;
  	}
  
--- 3845,3891 ----
  
  		/* compatible with postgresql 8.3 when DateStyle = 'iso' */
  		case INTSTYLE_POSTGRES:
! 			cp = AddPostgresIntervalPart(cp,year,"year",&is_zero,&is_before);
! 			cp = AddPostgresIntervalPart(cp,mon ,"mon" ,&is_zero,&is_before);
! 			cp = AddPostgresIntervalPart(cp,mday,"day" ,&is_zero,&is_before);
! 			if (is_zero || hour != 0 || min != 0 || sec != 0 || fsec != 0)
  			{
! 				int	minus = (hour < 0 || min < 0 ||
! 							 sec < 0 || fsec < 0);
! 				cp += sprintf(cp, "%s%s%02d:%02d:%02d", is_zero ? "" : " ",
  						(minus ? "-" : (is_before ? "+" : "")),
! 					  abs(hour), abs(min), abs(sec));
! 				AppendFsec(cp,fsec);
  			}
  			break;
  
  		/* compatible with postgresql 8.3 when DateStyle = 'sql' */
  		case INTSTYLE_POSTGRES_VERBOSE:
  		default:
! 			strcpy(cp, "@");
! 			cp++;
! 			cp = AddVerboseIntervalPart(cp,year,"year",&is_zero,&is_before);
! 			cp = AddVerboseIntervalPart(cp,mon ,"mon" ,&is_zero,&is_before);
! 			cp = AddVerboseIntervalPart(cp,mday,"day" ,&is_zero,&is_before);
! 			cp = AddVerboseIntervalPart(cp,hour,"hour",&is_zero,&is_before);
! 			cp = AddVerboseIntervalPart(cp,min ,"min" ,&is_zero,&is_before);
! 			if (sec != 0 || fsec != 0)
  			{
! 			    cp += sprintf(cp, " ");
! 				if (is_zero)
! 					is_before = (sec < 0);
! 				if (is_before ^ (sec < 0 || fsec < 0))
! 					cp += sprintf(cp, "-");
! 				cp += sprintf(cp, "%d", abs(sec));
! 				AppendFsec(cp,fsec);
  				cp += strlen(cp);
+ 				cp += sprintf(cp, " sec%s", (abs(sec) != 1 || fsec != 0) ? "s" : "");
+ 				is_zero = FALSE;
  			}
+ 			if (is_zero)
+ 				strcat(cp, " 0");
  			if (is_before)
  				strcat(cp, " ago");
  			break;
  	}
  
*** a/src/backend/utils/adt/nabstime.c
--- b/src/backend/utils/adt/nabstime.c
***************
*** 634,639 **** reltimein(PG_FUNCTION_ARGS)
--- 634,642 ----
  	if (dterr == 0)
  		dterr = DecodeInterval(field, ftype, nf, INTERVAL_FULL_RANGE,
  							   &dtype, tm, &fsec);
+ 	if (dterr == DTERR_BAD_FORMAT)
+ 	    dterr = DecodeISO8601Interval(str, tm, &fsec);
+ 
  	if (dterr != 0)
  	{
  		if (dterr == DTERR_FIELD_OVERFLOW)
***************
*** 646,651 **** reltimein(PG_FUNCTION_ARGS)
--- 649,664 ----
  		case DTK_DELTA:
  			result = ((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec;
  			result += tm->tm_year * SECS_PER_YEAR + ((tm->tm_mon * DAYS_PER_MONTH) + tm->tm_mday) * SECS_PER_DAY;
+ 			if (fsec != 0)
+ 			{
+ 				int			extra_seconds;
+ #ifdef HAVE_INT64_TIMESTAMP
+ 				extra_seconds = (fsec / INT64CONST(1000000));
+ #else
+ 				TMODULO(fsec, extra_seconds, 1e0);
+ #endif
+ 				result += extra_seconds;
+ 			}
  			break;
  
  		default: