From: Thomas Lockhart <Thomas.G.Lockhart@jpl.nasa.gov>

Subject: [HACKERS] More date time functions

Here are some additional patches mostly related to the date and time
data types. It includes some type conversion routines to move between
the different date types and some other date manipulation routines such
as date_part(units,datetime).

I noticed Edmund Mergl et al's neat trick for getting function overloading
for builtin functions, so started to use that for the date and time stuff.
Later, if someone figures out how to get function overloading directly
for internal C code, then we can move to that technique.

These patches include documentation updates (don't faint!) for the built-in
man page. Doesn't yet include mention of timestamp, since I don't know
much about it and since it may change a bit to become a _real_ ANSI timestamp
which would include parser support for the declaration syntax (what do you
think, Dan?).

The patches were developed on the 970330 release, but have been rebuilt
off of the 970402 release. The first patch below is to get libpq to compile,
on my Linux box, but is not related to the rest of the patches and you can
choose not to apply that one at this time. Thanks in advance, scrappy!

src/backend/utils/adt/dt.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/dt.c,v 1.13 1997/03/28 07:16:59 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/dt.c,v 1.14 1997/04/02 18:33:32 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,7 +19,7 @@
 #include <errno.h>
 
 #include "postgres.h"
-#include <miscadmin.h>
+#include "miscadmin.h"
 #ifdef HAVE_FLOAT_H
 # include <float.h>
 #endif
@@ -34,6 +34,10 @@
 #define USE_DATE_CACHE 1
 
 
+#define isleap(y) (((y % 4) == 0) && (((y % 100) != 0) || ((y % 400) == 0)))
+
+int mdays[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31, 0};
+
 char *months[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", NULL};
 
@@ -55,26 +59,26 @@ datetime_in(char *str)
 
     double fsec;
     struct tm tt, *tm = &tt;
-    int tzp;
+    int tz;
     int dtype;
     int nf;
     char *field[MAXDATEFIELDS];
     int ftype[MAXDATEFIELDS];
-    char lowstr[MAXDATELEN];
+    char lowstr[MAXDATELEN+1];
 
     if (!PointerIsValid(str))
-	elog(WARN, "Bad (null) datetime external representation", NULL);
+	elog(WARN,"Bad (null) datetime external representation",NULL);
 
     if ((ParseDateTime( str, lowstr, field, ftype, MAXDATEFIELDS, &nf) != 0)
-      || (DecodeDateTime( field, ftype, nf, &dtype, tm, &fsec, &tzp) != 0))
+      || (DecodeDateTime( field, ftype, nf, &dtype, tm, &fsec, &tz) != 0))
 	elog(WARN,"Bad datetime external representation %s",str);
 
     if (!PointerIsValid(result = PALLOCTYPE(DateTime)))
-	elog(WARN, "Memory allocation failed, can't input datetime '%s'",str);
+	elog(WARN,"Memory allocation failed, can't input datetime '%s'",str);
 
     switch (dtype) {
     case DTK_DATE:
-	*result = tm2datetime( tm, fsec, tzp);
+	*result = tm2datetime( tm, fsec, &tz);
 
 #ifdef DATEDEBUG
 printf( "datetime_in- date is %f\n", *result);
@@ -103,7 +107,7 @@ printf( "datetime_in- date is %f\n", *result);
 	break;
 
     default:
-	elog(WARN, "Internal coding error, can't input datetime '%s'",str);
+	elog(WARN,"Internal coding error, can't input datetime '%s'",str);
     };
 
     return(result);
@@ -118,7 +122,7 @@ datetime_out(DateTime *dt)
     char *result;
     struct tm tt, *tm = &tt;
     double fsec;
-    char buf[MAXDATELEN];
+    char buf[MAXDATELEN+1];
 
     if (!PointerIsValid(dt))
 	return(NULL);
@@ -126,7 +130,7 @@ datetime_out(DateTime *dt)
     if (DATETIME_IS_RESERVED(*dt)) {
 	EncodeSpecialDateTime(*dt, buf);
 
-    } else if (datetime2tm( *dt, tm, &fsec) == 0) {
+    } else if (datetime2tm( *dt, &CTimeZone, tm, &fsec) == 0) {
 	EncodeDateTime(tm, fsec, DateStyle, buf);
 
     } else {
@@ -134,7 +138,7 @@ datetime_out(DateTime *dt)
     };
 
     if (!PointerIsValid(result = PALLOC(strlen(buf)+1)))
-	elog(WARN, "Memory allocation failed, can't output datetime", NULL);
+	elog(WARN,"Memory allocation failed, can't output datetime",NULL);
 
     strcpy( result, buf);
 
@@ -159,7 +163,7 @@ timespan_in(char *str)
     int nf;
     char *field[MAXDATEFIELDS];
     int ftype[MAXDATEFIELDS];
-    char lowstr[MAXDATELEN];
+    char lowstr[MAXDATELEN+1];
 
     tm->tm_year = 0;
     tm->tm_mon = 0;
@@ -170,14 +174,14 @@ timespan_in(char *str)
     fsec = 0;
 
     if (!PointerIsValid(str))
-	elog(WARN, "Bad (null) timespan external representation", NULL);
+	elog(WARN,"Bad (null) timespan external representation",NULL);
 
     if ((ParseDateTime( str, lowstr, field, ftype, MAXDATEFIELDS, &nf) != 0)
       || (DecodeDateDelta( field, ftype, nf, &dtype, tm, &fsec) != 0))
 	elog(WARN,"Bad timespan external representation %s",str);
 
     if (!PointerIsValid(span = PALLOCTYPE(TimeSpan)))
-	elog(WARN, "Memory allocation failed, can't input timespan '%s'",str);
+	elog(WARN,"Memory allocation failed, can't input timespan '%s'",str);
 
     switch (dtype) {
     case DTK_DELTA:
@@ -189,7 +193,7 @@ timespan_in(char *str)
 	break;
 
     default:
-	elog(WARN, "Internal coding error, can't input timespan '%s'",str);
+	elog(WARN,"Internal coding error, can't input timespan '%s'",str);
     };
 
     return(span);
@@ -205,7 +209,7 @@ timespan_out(TimeSpan *span)
 
     struct tm tt, *tm = &tt;
     double fsec;
-    char buf[MAXDATELEN];
+    char buf[MAXDATELEN+1];
 
     if (!PointerIsValid(span))
 	return(NULL);
@@ -229,6 +233,26 @@ timespan_out(TimeSpan *span)
  *****************************************************************************/
 
 
+bool
+datetime_finite(DateTime *datetime)
+{
+    if (!PointerIsValid(datetime))
+	return FALSE;
+
+    return(! DATETIME_NOT_FINITE(*datetime));
+} /* datetime_finite() */
+
+
+bool
+timespan_finite(TimeSpan *timespan)
+{
+    if (!PointerIsValid(timespan))
+	return FALSE;
+
+    return(! TIMESPAN_NOT_FINITE(*timespan));
+} /* timespan_finite() */
+
+
 /*----------------------------------------------------------
  *  Relational operators for datetime.
  *---------------------------------------------------------*/
@@ -267,14 +291,14 @@ SetDateTime( DateTime dt) {
 
     if (DATETIME_IS_CURRENT(dt)) {
 	GetCurrentTime(&tt);
-	dt = tm2datetime( &tt, 0, 0);
+	dt = tm2datetime( &tt, 0, NULL);
 
 #ifdef DATEDEBUG
 printf( "SetDateTime- current time is %f\n", dt);
 #endif
     } else { /* if (DATETIME_IS_EPOCH(dt1)) */
 	GetEpochTime(&tt);
-	dt = tm2datetime( &tt, 0, 0);
+	dt = tm2datetime( &tt, 0, NULL);
 #ifdef DATEDEBUG
 printf( "SetDateTime- epoch time is %f\n", dt);
 #endif
@@ -520,7 +544,7 @@ TimeSpan *datetime_sub(DateTime *datetime1, DateTime *datetime2)
     dt2 = *datetime2;
 
     if (!PointerIsValid(result = PALLOCTYPE(TimeSpan)))
-	elog(WARN, "Memory allocation failed, can't subtract dates",NULL);
+	elog(WARN,"Memory allocation failed, can't subtract dates",NULL);
 
     if (DATETIME_IS_RELATIVE(dt1)) dt1 = SetDateTime(dt1);
     if (DATETIME_IS_RELATIVE(dt2)) dt2 = SetDateTime(dt2);
@@ -538,46 +562,83 @@ TimeSpan *datetime_sub(DateTime *datetime1, DateTime *datetime2)
 } /* datetime_sub() */
 
 
+/* datetime_add_span()
+ * Add a timespan to a datetime data type.
+ * Note that timespan has provisions for qualitative year/month
+ *  units, so try to do the right thing with them.
+ * To add a month, increment the month, and use the same day of month.
+ * Then, if the next month has fewer days, set the day of month
+ *  to the last day of month.
+ */
 DateTime *datetime_add_span(DateTime *datetime, TimeSpan *span)
 {
     DateTime *result;
 
+#if FALSE
     double date, time;
     int year, mon, mday;
+#endif
 
     if ((!PointerIsValid(datetime)) || (!PointerIsValid(span)))
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(DateTime)))
-	elog(WARN, "Memory allocation failed, can't add dates",NULL);
+	elog(WARN,"Memory allocation failed, can't add dates",NULL);
 
 #ifdef DATEDEBUG
-printf( "date_add- add %f to %d %f\n", *datetime, span->month, span->time);
+printf( "datetime_add_span- add %f to %d %f\n", *datetime, span->month, span->time);
 #endif
 
-    *result = *datetime;
-    if (DATETIME_IS_RELATIVE(*result)) *result = SetDateTime(*result);
+    if (DATETIME_NOT_FINITE(*datetime)) {
+	*result = *datetime;
 
-    if (span->month != 0) {
-	time = JROUND(modf( (*result/86400), &date)*86400);
-	date += date2j(2000,1,1);
+    } else if (TIMESPAN_IS_INVALID(*span)) {
+	DATETIME_INVALID(*result);
 
-	j2date( ((int) date), &year, &mon, &mday);
-	mon += span->month;
-	if (mon > 12) {
-	    year += mon / 12;
-	    mon %= 12;
-	} else if (mon < 0) {
-	    year += mon / 12;
-	    mon %= 12;
-	    year -= 1;
-	    mon += 12;
+    } else {
+	*result = (DATETIME_IS_RELATIVE(*datetime)? SetDateTime(*datetime): *datetime);
+
+	if (span->month != 0) {
+	    struct tm tt, *tm = &tt;
+	    double fsec;
+
+	    if (datetime2tm( *result, NULL, tm, &fsec) == 0) {
+#ifdef DATEDEBUG
+printf( "datetime_add_span- date was %d.%02d.%02d\n", tm->tm_year, tm->tm_mon, tm->tm_mday);
+#endif
+		tm->tm_mon += span->month;
+		if (tm->tm_mon > 12) {
+		    tm->tm_year += (tm->tm_mon / 12);
+		    tm->tm_mon = (tm->tm_mon % 12);
+		} else if (tm->tm_mon < 1) {
+		    tm->tm_year += ((tm->tm_mon / 12) - 1);
+		    tm->tm_mon = ((tm->tm_mon % 12) + 12);
+		};
+
+		/* adjust for end of month boundary problems... */
+		if (tm->tm_mday > mdays[ tm->tm_mon-1]) {
+		    if ((tm->tm_mon == 2) && isleap( tm->tm_year)) {
+			tm->tm_mday = (mdays[ tm->tm_mon-1]+1);
+		    } else {
+			tm->tm_mday = mdays[ tm->tm_mon-1];
+		    };
+		};
+
+#ifdef DATEDEBUG
+printf( "datetime_add_span- date becomes %d.%02d.%02d\n", tm->tm_year, tm->tm_mon, tm->tm_mday);
+#endif
+		*result = tm2datetime( tm, fsec, NULL);
+
+	    } else {
+		DATETIME_INVALID(*result);
+	    };
 	};
-	*result += ((date2j( year, mon, mday)-date2j(2000,1,1))*86400);
-	*result += time;
-    };
 
-    *result = JROUND(*result + span->time);
+#if FALSE
+	*result = JROUND(*result + span->time);
+#endif
+	*result += span->time;
+    };
 
     return(result);
 } /* datetime_add_span() */
@@ -607,13 +668,13 @@ TimeSpan *timespan_um(TimeSpan *timespan)
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(TimeSpan)))
-	elog(WARN, "Memory allocation failed, can't subtract dates",NULL);
+	elog(WARN,"Memory allocation failed, can't subtract dates",NULL);
 
     result->time = -(timespan->time);
     result->month = -(timespan->month);
 
     return(result);
-} /* datetime_sub() */
+} /* timespan_um() */
 
 
 TimeSpan *timespan_add(TimeSpan *span1, TimeSpan *span2)
@@ -624,7 +685,7 @@ TimeSpan *timespan_add(TimeSpan *span1, TimeSpan *span2)
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(TimeSpan)))
-	elog(WARN, "Memory allocation failed, can't add timespans",NULL);
+	elog(WARN,"Memory allocation failed, can't add timespans",NULL);
 
     result->month = (span1->month + span2->month);
     result->time = JROUND(span1->time + span2->time);
@@ -640,7 +701,7 @@ TimeSpan *timespan_sub(TimeSpan *span1, TimeSpan *span2)
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(TimeSpan)))
-	elog(WARN, "Memory allocation failed, can't subtract timespans",NULL);
+	elog(WARN,"Memory allocation failed, can't subtract timespans",NULL);
 
     result->month = (span1->month - span2->month);
     result->time = JROUND(span1->time - span2->time);
@@ -654,6 +715,125 @@ TimeSpan *timespan_sub(TimeSpan *span1, TimeSpan *span2)
  *---------------------------------------------------------*/
 
 
+/* datetime_text()
+ * Convert datetime to text data type.
+ */
+text *
+datetime_text(DateTime *datetime)
+{
+    text *result;
+    char *str;
+    int len;
+
+    if (!PointerIsValid(datetime))
+	return NULL;
+
+    str = datetime_out(datetime);
+
+    if (!PointerIsValid(str))
+	return NULL;
+
+    len = (strlen(str)+VARHDRSZ);
+
+    if (!PointerIsValid(result = PALLOC(len)))
+	elog(WARN,"Memory allocation failed, can't convert datetime to text",NULL);
+
+    VARSIZE(result) = len;
+    memmove(VARDATA(result), str, (len-VARHDRSZ));
+
+    PFREE(str);
+
+    return(result);
+} /* datetime_text() */
+
+
+/* text_datetime()
+ * Convert text string to datetime.
+ * Text type is not null terminated, so use temporary string
+ *  then call the standard input routine.
+ */
+DateTime *
+text_datetime(text *str)
+{
+    DateTime *result;
+    int i;
+    char *sp, *dp, dstr[MAXDATELEN+1];
+
+    if (!PointerIsValid(str))
+	return NULL;
+
+    sp = VARDATA(str);
+    dp = dstr;
+    for (i = 0; i < (VARSIZE(str)-VARHDRSZ); i++) *dp++ = *sp++;
+    *dp = '\0';
+
+    result = datetime_in(dstr);
+
+    return(result);
+} /* text_datetime() */
+
+
+/* timespan_text()
+ * Convert timespan to text data type.
+ */
+text *
+timespan_text(TimeSpan *timespan)
+{
+    text *result;
+    char *str;
+    int len;
+
+    if (!PointerIsValid(timespan))
+	return NULL;
+
+    str = timespan_out(timespan);
+
+    if (!PointerIsValid(str))
+	return NULL;
+
+    len = (strlen(str)+VARHDRSZ);
+
+    if (!PointerIsValid(result = PALLOC(len)))
+	elog(WARN,"Memory allocation failed, can't convert timespan to text",NULL);
+
+    VARSIZE(result) = len;
+    memmove(VARDATA(result), str, (len-VARHDRSZ));
+
+    PFREE(str);
+
+    return(result);
+} /* timespan_text() */
+
+
+/* text_timespan()
+ * Convert text string to timespan.
+ * Text type may not be null terminated, so copy to temporary string
+ *  then call the standard input routine.
+ */
+TimeSpan *
+text_timespan(text *str)
+{
+    TimeSpan *result;
+    int i;
+    char *sp, *dp, dstr[MAXDATELEN+1];
+
+    if (!PointerIsValid(str))
+	return NULL;
+
+    sp = VARDATA(str);
+    dp = dstr;
+    for (i = 0; i < (VARSIZE(str)-VARHDRSZ); i++) *dp++ = *sp++;
+    *dp = '\0';
+
+    result = timespan_in(dstr);
+
+    return(result);
+} /* text_timespan() */
+
+
+/* datetime_part()
+ * Extract specified field from datetime.
+ */
 float64
 datetime_part(text *units, DateTime *datetime)
 {
@@ -662,7 +842,7 @@ datetime_part(text *units, DateTime *datetime)
     DateTime dt;
     int type, val;
     int i;
-    char *up, *lp, lowunits[MAXDATELEN];
+    char *up, *lp, lowunits[MAXDATELEN+1];
     double fsec;
     struct tm tt, *tm = &tt;
 
@@ -670,7 +850,7 @@ datetime_part(text *units, DateTime *datetime)
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(float64data)))
-	elog(WARN, "Memory allocation failed, can't get date part",NULL);
+	elog(WARN,"Memory allocation failed, can't get date part",NULL);
 
     up = VARDATA(units);
     lp = lowunits;
@@ -694,7 +874,7 @@ printf( "datetime_part- units %s type=%d value=%d\n", lowunits, type, val);
 
 	dt = (DATETIME_IS_RELATIVE(*datetime)? SetDateTime(*datetime): *datetime); 
 
-	if (datetime2tm( dt, tm, &fsec) == 0) {
+	if (datetime2tm( dt, &CTimeZone, tm, &fsec) == 0) {
 	    switch (val) {
 	    case DTK_TZ:
 		*result = CTimeZone;
@@ -768,6 +948,9 @@ printf( "datetime_part- units %s type=%d value=%d\n", lowunits, type, val);
 } /* datetime_part() */
 
 
+/* timespan_part()
+ * Extract specified field from timespan.
+ */
 float64
 timespan_part(text *units, TimeSpan *timespan)
 {
@@ -775,7 +958,7 @@ timespan_part(text *units, TimeSpan *timespan)
 
     int type, val;
     int i;
-    char *up, *lp, lowunits[MAXDATELEN];
+    char *up, *lp, lowunits[MAXDATELEN+1];
     double fsec;
     struct tm tt, *tm = &tt;
 
@@ -783,7 +966,7 @@ timespan_part(text *units, TimeSpan *timespan)
 	return NULL;
 
     if (!PointerIsValid(result = PALLOCTYPE(float64data)))
-	elog(WARN, "Memory allocation failed, can't get date part",NULL);
+	elog(WARN,"Memory allocation failed, can't get date part",NULL);
 
     up = VARDATA(units);
     lp = lowunits;
@@ -879,10 +1062,6 @@ printf( "timespan_part- units %s type=%d value=%d\n", lowunits, type, val);
  *   PRIVATE ROUTINES                                                        *
  *****************************************************************************/
 
-#if USE_NEW_TIME_CODE
-#define DATE_MAXLEN	47
-#endif
-
 /* definitions for squeezing values into "value" */
 #define ABS_SIGNBIT	0200
 #define VALMASK		0177
@@ -1218,11 +1397,12 @@ int j2day( int date)
  * Also, month is one-based, _not_ zero-based.
  */
 int
-datetime2tm( DateTime dt, struct tm *tm, double *fsec)
+datetime2tm( DateTime dt, int *tzp, struct tm *tm, double *fsec)
 {
     double date, time, sec;
 
-    time = (modf( dt2local( dt, CTimeZone)/86400, &date)*86400);
+    if (tzp != NULL) dt = dt2local( dt, *tzp);
+    time = (modf( dt/86400, &date)*86400);
     date += date2j(2000,1,1);
     if (time < 0) {
 	    time += 86400;
@@ -1233,7 +1413,8 @@ datetime2tm( DateTime dt, struct tm *tm, double *fsec)
     if (date < 0) return -1;
 
 #ifdef DATEDEBUG
-printf( "datetime2tm- date is %f (%f %f)\n", dt, date, time);
+printf( "datetime2tm- date is %f (%f %f)\n",
+ ((tzp != NULL)? dt2local(dt, -(*tzp)): dt), date, time);
 #endif
 
     j2date((int) date, &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
@@ -1254,8 +1435,8 @@ printf( "datetime2tm- time is %02d:%02d:%02d %.7f\n", tm->tm_hour, tm->tm_min, t
     tm->tm_isdst = -1;
 
 #ifdef DATEDEBUG
-printf( "datetime2tm- timezone is %s; offset is %d; daylight is %d\n",
- CTZName, CTimeZone, CDayLight);
+printf( "datetime2tm- timezone is %s; offset is %d (%d); daylight is %d\n",
+ CTZName, ((tzp != NULL)? *tzp: 0), CTimeZone, CDayLight);
 #endif
 
     return 0;
@@ -1268,7 +1449,7 @@ printf( "datetime2tm- timezone is %s; offset is %d; daylight is %d\n",
  * Also, month is one-based, _not_ zero-based.
  */
 DateTime
-tm2datetime( struct tm *tm, double fsec, int tzp) {
+tm2datetime( struct tm *tm, double fsec, int *tzp) {
 
     DateTime result;
     double date, time;
@@ -1284,7 +1465,7 @@ tm2datetime( struct tm *tm, double fsec, int tzp) {
 printf( "tm2datetime- date is %f (%f %f %d)\n", result, date, time, (((tm->tm_hour*60)+tm->tm_min)*60+tm->tm_sec));
 printf( "tm2datetime- time is %f %02d:%02d:%02d %f\n", time, tm->tm_hour, tm->tm_min, tm->tm_sec, fsec);
 #endif
-    if (tzp != 0) result = dt2local(result, -tzp);
+    if (tzp != NULL) result = dt2local(result, -(*tzp));
 
     return(result);
 } /* tm2datetime() */
@@ -1832,40 +2013,17 @@ DecodeDate(char *str, int fmask, int *tmask, struct tm *tm)
 
     *tmask = 0;
 
+    /* look first for text fields, since that will be unambiguous month */
     for (i = 0; i < nf; i++) {
-	str = field[i];
-	len = strlen(str);
-
-	if (len <= 0)
-	    return -1;
-
-	if (isdigit(*str)) {
-	    if (DecodeNumber( len, str, fmask, &dmask, tm, &fsec) != 0)
-		return -1;
-
-	} else if (isalpha(*str)) {
+	if (isalpha(*field[i])) {
 	    type = DecodeSpecial( i, field[i], &val);
 	    if (type == IGNORE) continue;
 
 	    dmask = DTK_M(type);
 	    switch (type) {
-	    case YEAR:
-#ifdef DATEDEBUG
-printf( "DecodeDate- year field %s value is %d\n", field[i], val); 
-#endif
-		tm->tm_mon = val;
-		break;
-
 	    case MONTH:
 #ifdef DATEDEBUG
 printf( "DecodeDate- month field %s value is %d\n", field[i], val); 
-#endif
-		tm->tm_mon = val;
-		break;
-
-	    case DAY:
-#ifdef DATEDEBUG
-printf( "DecodeDate- month field %s value is %d\n", field[i], val); 
 #endif
 		tm->tm_mon = val;
 		break;
@@ -1876,7 +2034,25 @@ printf( "DecodeDate- illegal field %s value is %d\n", field[i], val);
 #endif
 		return -1;
 	    };
+	    if (fmask & dmask) return -1;
+
+	    fmask |= dmask;
+	    *tmask |= dmask;
+
+	    /* mark this field as being completed */
+	    field[i] = NULL;
 	};
+    };
+
+    /* now pick up remaining numeric fields */
+    for (i = 0; i < nf; i++) {
+	if (field[i] == NULL) continue;
+
+	if ((len = strlen(field[i])) <= 0)
+	    return -1;
+
+	if (DecodeNumber( len, field[i], fmask, &dmask, tm, &fsec) != 0)
+	    return -1;
 
 	if (fmask & dmask) return -1;
 
@@ -1955,6 +2131,19 @@ printf( "DecodeNumber- %s is %d fmask=%08x tmask=%08x\n", str, val, fmask, *tmas
 printf( "DecodeNumber- match %d (%s) as year\n", val, str);
 #endif
 	*tmask = DTK_M(YEAR);
+
+	/* already have a year? then see if we can substitute... */
+	if (fmask & DTK_M(YEAR)) {
+	    if ((!(fmask & DTK_M(DAY)))
+	     && ((tm->tm_year >= 1) && (tm->tm_year <= 31))) {
+#ifdef DATEDEBUG
+printf( "DecodeNumber- misidentified year previously; swap with day %d\n", tm->tm_mday);
+#endif
+		tm->tm_mday = tm->tm_year;
+		*tmask = DTK_M(DAY);
+	    };
+	};
+
 	tm->tm_year = val;
 
     /* special case day of year? */
@@ -1966,7 +2155,7 @@ printf( "DecodeNumber- match %d (%s) as year\n", val, str);
 	  &tm->tm_year,&tm->tm_mon,&tm->tm_mday);
 
     /* already have year? then could be month */
-    } else if ((fmask && DTK_M(YEAR)) && (! (fmask & DTK_M(MONTH)))
+    } else if ((fmask & DTK_M(YEAR)) && (! (fmask & DTK_M(MONTH)))
       && ((val >= 1) && (val <= 12))) {
 #ifdef DATEDEBUG
 printf( "DecodeNumber- match %d (%s) as month\n", val, str);
@@ -1975,11 +2164,7 @@ printf( "DecodeNumber- match %d (%s) as month\n", val, str);
 	tm->tm_mon = val;
 
     /* no year and EuroDates enabled? then could be day */
-#if USE_EURODATES
     } else if ((EuroDates || (fmask & DTK_M(MONTH)))
-#else
-    } else if ((fmask & DTK_M(MONTH))
-#endif
       && (! ((fmask & DTK_M(YEAR)) && (fmask & DTK_M(DAY))))
       && ((val >= 1) && (val <= 31))) {
 #ifdef DATEDEBUG
@@ -1996,6 +2181,14 @@ printf( "DecodeNumber- (2) match %d (%s) as month\n", val, str);
 	*tmask = DTK_M(MONTH);
 	tm->tm_mon = val;
 
+    } else if ((! (fmask & DTK_M(DAY)))
+      && ((val >= 1) && (val <= 31))) {
+#ifdef DATEDEBUG
+printf( "DecodeNumber- (2) match %d (%s) as day\n", val, str);
+#endif
+	*tmask = DTK_M(DAY);
+	tm->tm_mday = val;
+
     } else if (! (fmask & DTK_M(YEAR))) {
 #ifdef DATEDEBUG
 printf( "DecodeNumber- (2) match %d (%s) as year\n", val, str);
@@ -2467,7 +2660,7 @@ int EncodeDateTime(struct tm *tm, double fsec, int style, char *str)
     int day, hour, min;
     double sec;
 #ifdef DATEDEBUG
-    char buf[MAXDATELEN];
+    char buf[MAXDATELEN+1];
 #endif
 
     sec = (tm->tm_sec + fsec);