parsedata.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1992-2009 Edwin Groothuis <[email protected]>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/cdefs.h>
#include <ctype.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>

#include "calendar.h"

#define	SLEN	100	/* maximum length of date spec. part strings */

static char *showflags(int flags);
static int isonlydigits(char *s, int nostar);
static const char *getmonthname(int i);
static int checkmonth(char *s, size_t *len, size_t *offset, const char **month);
static const char *getdayofweekname(int i);
static int checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow);
static int indextooffset(char *s);
static int parseoffset(char *s);
static char *floattoday(int year, double f);
static char *floattotime(double f);
static int wdayom (int day, int offset, int month, int year);

/*
 * Expected styles:
 *
 * Date			::=	Month . ' ' . DayOfMonth |
 *				Month . ' ' . DayOfWeek . ModifierIndex |
 *				Month . '/' . DayOfMonth |
 *				Month . '/' . DayOfWeek . ModifierIndex |
 *				DayOfMonth . ' ' . Month |
 *				DayOfMonth . '/' . Month |
 *				DayOfWeek . ModifierIndex . ' ' .Month |
 *				DayOfWeek . ModifierIndex . '/' .Month |
 *				DayOfWeek . ModifierIndex |
 *				SpecialDay . ModifierOffset
 *
 * Month		::=	MonthName | MonthNumber | '*'
 * MonthNumber		::=	'0' ... '9' | '00' ... '09' | '10' ... '12'
 * MonthName		::=	MonthNameShort | MonthNameLong
 * MonthNameLong	::=	'January' ... 'December'
 * MonthNameShort	::=	'Jan' ... 'Dec' | 'Jan.' ... 'Dec.'
 *
 * DayOfWeek		::=	DayOfWeekShort | DayOfWeekLong
 * DayOfWeekShort	::=	'Mon' .. 'Sun'
 * DayOfWeekLong	::=	'Monday' .. 'Sunday'
 * DayOfMonth		::=	'0' ... '9' | '00' ... '09' | '10' ... '29' |
 *				'30' ... '31' | '*'
 *
 * ModifierOffset	::=	'' | '+' . ModifierNumber | '-' . ModifierNumber
 * ModifierNumber	::=	'0' ... '9' | '00' ... '99' | '000' ... '299' |
 *				'300' ... '359' | '360' ... '365'
 * ModifierIndex	::=	'Second' | 'Third' | 'Fourth' | 'Fifth' |
 *				'First' | 'Last'
 *
 * SpecialDay		::=	'Easter' | 'Paskha' | 'ChineseNewYear'
 *
 */
static int
determinestyle(char *date, int *flags,
    char *month, int *imonth, char *dayofmonth, int *idayofmonth,
    char *dayofweek, int *idayofweek, char *modifieroffset,
    char *modifierindex, char *specialday, char *year, int *iyear)
{
	char *p, *p1, *p2, *py;
	const char *dow, *pmonth;
	char pold;
	size_t len, offset;

	*flags = F_NONE;
	*month = '\0';
	*imonth = 0;
	*year = '\0';
	*iyear = 0;
	*dayofmonth = '\0';
	*idayofmonth = 0;
	*dayofweek = '\0';
	*idayofweek = 0;
	*modifieroffset = '\0';
	*modifierindex = '\0';
	*specialday = '\0';

#define CHECKSPECIAL(s1, s2, lens2, type)				\
	if (s2 != NULL && strncmp(s1, s2, lens2) == 0) {		\
		*flags |= F_SPECIALDAY;					\
		*flags |= type;						\
		*flags |= F_VARIABLE;					\
		if (strlen(s1) == lens2) {				\
			strlcpy(specialday, s1, SLEN);			\
			return (1);					\
		}							\
		strncpy(specialday, s1, lens2);				\
		specialday[lens2] = '\0';				\
		strlcpy(modifieroffset, s1 + lens2, SLEN);		\
		*flags |= F_MODIFIEROFFSET;				\
		return (1);						\
	}

	if ((p = strchr(date, ' ')) == NULL) {
		if ((p = strchr(date, '/')) == NULL) {
			CHECKSPECIAL(date, STRING_CNY, strlen(STRING_CNY),
			    F_CNY);
			CHECKSPECIAL(date, ncny.name, ncny.len, F_CNY);
			CHECKSPECIAL(date, STRING_NEWMOON,
			    strlen(STRING_NEWMOON), F_NEWMOON);
			CHECKSPECIAL(date, nnewmoon.name, nnewmoon.len,
			    F_NEWMOON);
			CHECKSPECIAL(date, STRING_FULLMOON,
			    strlen(STRING_FULLMOON), F_FULLMOON);
			CHECKSPECIAL(date, nfullmoon.name, nfullmoon.len,
			    F_FULLMOON);
			CHECKSPECIAL(date, STRING_PASKHA,
			    strlen(STRING_PASKHA), F_PASKHA);
			CHECKSPECIAL(date, npaskha.name, npaskha.len, F_PASKHA);
			CHECKSPECIAL(date, STRING_EASTER,
			    strlen(STRING_EASTER), F_EASTER);
			CHECKSPECIAL(date, neaster.name, neaster.len, F_EASTER);
			CHECKSPECIAL(date, STRING_MAREQUINOX,
			    strlen(STRING_MAREQUINOX), F_MAREQUINOX);
			CHECKSPECIAL(date, nmarequinox.name, nmarequinox.len,
			    F_SEPEQUINOX);
			CHECKSPECIAL(date, STRING_SEPEQUINOX,
			    strlen(STRING_SEPEQUINOX), F_SEPEQUINOX);
			CHECKSPECIAL(date, nsepequinox.name, nsepequinox.len,
			    F_SEPEQUINOX);
			CHECKSPECIAL(date, STRING_JUNSOLSTICE,
			    strlen(STRING_JUNSOLSTICE), F_JUNSOLSTICE);
			CHECKSPECIAL(date, njunsolstice.name, njunsolstice.len,
			    F_JUNSOLSTICE);
			CHECKSPECIAL(date, STRING_DECSOLSTICE,
			    strlen(STRING_DECSOLSTICE), F_DECSOLSTICE);
			CHECKSPECIAL(date, ndecsolstice.name, ndecsolstice.len,
			    F_DECSOLSTICE);
			if (checkdayofweek(date, &len, &offset, &dow) != 0) {
				*flags |= F_DAYOFWEEK;
				*flags |= F_VARIABLE;
				*idayofweek = offset;
				if (strlen(date) == len) {
					strlcpy(dayofweek, date, SLEN);
					return (1);
				}
				strncpy(dayofweek, date, len);
				dayofweek[len] = '\0';
				strlcpy(modifierindex, date + len, SLEN);
				*flags |= F_MODIFIERINDEX;
				return (1);
			}
			if (isonlydigits(date, 1)) {
				/* Assume month number only */
				*flags |= F_MONTH;
				*imonth = (int)strtol(date, (char **)NULL, 10);
				strlcpy(month, getmonthname(*imonth), SLEN);
				return(1);
			}
			return (0);
		}
	}

	/*
	 * After this, leave by goto-ing to "allfine" or "fail" to restore the
	 * original data in `date'.
	 */
	pold = *p;
	*p = 0;
	p1 = date;
	p2 = p + 1;
	/* Now p2 points to the next field and p1 to the first field */

	if ((py = strchr(p2, '/')) != NULL) {
		/* We have a year in the string. Now this is getting tricky */
		strlcpy(year, p1, SLEN);
		*iyear = (int)strtol(year, NULL, 10);
		p1 = p2;
		p2 = py + 1;
		*py = 0;
		*flags |= F_YEAR;
	}

	/* Check if there is a month-string in the date */
	if ((checkmonth(p1, &len, &offset, &pmonth) != 0)
	    || (checkmonth(p2, &len, &offset, &pmonth) != 0 && (p2 = p1))) {
		/* p2 is the non-month part */
		*flags |= F_MONTH;
		*imonth = offset;

		strlcpy(month, getmonthname(offset), SLEN);
		if (isonlydigits(p2, 1)) {
			strlcpy(dayofmonth, p2, SLEN);
			*idayofmonth = (int)strtol(p2, (char **)NULL, 10);
			*flags |= F_DAYOFMONTH;
			goto allfine;
		}
		if (strcmp(p2, "*") == 0) {
			*flags |= F_ALLDAY;
			goto allfine;
		}

		if (checkdayofweek(p2, &len, &offset, &dow) != 0) {
			*flags |= F_DAYOFWEEK;
			*flags |= F_VARIABLE;
			*idayofweek = offset;
			strlcpy(dayofweek, getdayofweekname(offset), SLEN);
			if (strlen(p2) == len)
				goto allfine;
			strlcpy(modifierindex, p2 + len, SLEN);
			*flags |= F_MODIFIERINDEX;
			goto allfine;
		}
		goto fail;
	}

	/* Check if there is an every-day or every-month in the string */
	if ((strcmp(p1, "*") == 0 && isonlydigits(p2, 1))
	    || (strcmp(p2, "*") == 0 && isonlydigits(p1, 1) && (p2 = p1))) {
		int d;

		*flags |= F_ALLMONTH;
		*flags |= F_DAYOFMONTH;
		d = (int)strtol(p2, (char **)NULL, 10);
		*idayofmonth = d;
		snprintf(dayofmonth, SLEN, "%d", d);
		goto allfine;
	}

	/* Month as a number, then a weekday */
	if (isonlydigits(p1, 1)
	    && checkdayofweek(p2, &len, &offset, &dow) != 0) {
		int d;

		*flags |= F_MONTH;
		*flags |= F_DAYOFWEEK;
		*flags |= F_VARIABLE;

		*idayofweek = offset;
		d = (int)strtol(p1, (char **)NULL, 10);
		*imonth = d;
		strlcpy(month, getmonthname(d), SLEN);

		strlcpy(dayofweek, getdayofweekname(offset), SLEN);
		if (strlen(p2) == len)
			goto allfine;
		strlcpy(modifierindex, p2 + len, SLEN);
		*flags |= F_MODIFIERINDEX;
		goto allfine;
	}

	/* If both the month and date are specified as numbers */
	if (isonlydigits(p1, 1) && isonlydigits(p2, 0)) {
		/* Now who wants to be this ambiguous? :-( */
		int m, d;

		if (strchr(p2, '*') != NULL)
			*flags |= F_VARIABLE;

		m = (int)strtol(p1, (char **)NULL, 10);
		d = (int)strtol(p2, (char **)NULL, 10);

		*flags |= F_MONTH;
		*flags |= F_DAYOFMONTH;

		if (m > 12) {
			*imonth = d;
			*idayofmonth = m;
			strlcpy(month, getmonthname(d), SLEN);
			snprintf(dayofmonth, SLEN, "%d", m);
		} else {
			*imonth = m;
			*idayofmonth = d;
			strlcpy(month, getmonthname(m), SLEN);
			snprintf(dayofmonth, SLEN, "%d", d);
		}
		goto allfine;
	}

	/* FALLTHROUGH */
fail:
	*p = pold;
	return (0);
allfine:
	*p = pold;
	return (1);

}

static void
remember(int *rememberindex, int *y, int *m, int *d, char **ed, int yy, int mm,
    int dd, char *extra)
{
	static int warned = 0;

	if (*rememberindex >= MAXCOUNT - 1) {
		if (warned == 0)
			warnx("Index > %d, ignored", MAXCOUNT);
		warned++;
		return;
	}
	y[*rememberindex] = yy;
	m[*rememberindex] = mm;
	d[*rememberindex] = dd;
	if (extra != NULL)
		strlcpy(ed[*rememberindex], extra, SLEN);
	else
		ed[*rememberindex][0] = '\0';
	*rememberindex += 1;
}

static void
debug_determinestyle(int dateonly, char *date, int flags, char *month,
    int imonth, char *dayofmonth, int idayofmonth, char *dayofweek,
    int idayofweek, char *modifieroffset, char *modifierindex, char *specialday,
    char *year, int iyear)
{

	if (dateonly != 0) {
		printf("-------\ndate: |%s|\n", date);
		if (dateonly == 1)
			return;
	}
	printf("flags: %x - %s\n", flags, showflags(flags));
	if (modifieroffset[0] != '\0')
		printf("modifieroffset: |%s|\n", modifieroffset);
	if (modifierindex[0] != '\0')
		printf("modifierindex: |%s|\n", modifierindex);
	if (year[0] != '\0')
		printf("year: |%s| (%d)\n", year, iyear);
	if (month[0] != '\0')
		printf("month: |%s| (%d)\n", month, imonth);
	if (dayofmonth[0] != '\0')
		printf("dayofmonth: |%s| (%d)\n", dayofmonth, idayofmonth);
	if (dayofweek[0] != '\0')
		printf("dayofweek: |%s| (%d)\n", dayofweek, idayofweek);
	if (specialday[0] != '\0')
		printf("specialday: |%s|\n", specialday);
}

static struct yearinfo {
	int year;
	int ieaster, ipaskha, firstcnyday;
	double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
	double ffullmooncny[MAXMOONS], fnewmooncny[MAXMOONS];
	int ichinesemonths[MAXMOONS];
	double equinoxdays[2], solsticedays[2];
	int *monthdays;
	struct yearinfo *next;
} *years, *yearinfo;

/*
 * Calculate dates with offset from weekdays, like Thurs-3, Wed+2, etc.
 * day is the day of the week,
 * offset the ordinal number of the weekday in the month.
 */
static int
wdayom (int day, int offset, int month, int year)
{
/* Weekday of first day in month */
	int wday1;                                /* first day of month */
/* Weekday of last day in month */
	int wdayn;
	int d;

	wday1 = first_dayofweek_of_month(year, month);
	if (wday1 < 0)                          /* not set */
		return (wday1);
	/*
	 * Date of zeroth or first of our weekday in month, depending on the
	 * relationship with the first of the month.  The range is -6:6.
	 */
	d = (day - wday1 + 1) % 7;
	/*
	 * Which way are we counting?  Offset 0 is invalid, abs (offset) > 5 is
	 * meaningless, but that's OK.  Offset 5 may or may not be meaningless,
	 * so there's no point in complaining for complaining's sake.
	 */
	if (offset < 0) {			/* back from end of month */
						/* FIXME */
		wdayn = d;
		while (wdayn <= yearinfo->monthdays[month])
			wdayn += 7;
		d = offset * 7 + wdayn;
	} else if (offset > 0){
		if (d > 0)
			d += offset * 7 - 7;
		else
			d += offset * 7;
	} else
		warnx ("Invalid offset 0");
	return (d);
}

/*
 * Possible date formats include any combination of:
 *	3-charmonth			(January, Jan, Jan)
 *	3-charweekday			(Friday, Monday, mon.)
 *	numeric month or day		(1, 2, 04)
 *
 * Any character may separate them, or they may not be separated.  Any line,
 * following a line that is matched, that starts with "whitespace", is shown
 * along with the matched line.
 */
int
parsedaymonth(char *date, int *yearp, int *monthp, int *dayp, int *flags,
    char **edp)
{
	char month[SLEN], dayofmonth[SLEN], dayofweek[SLEN], modifieroffset[SLEN];
	char syear[SLEN];
	char modifierindex[SLEN], specialday[SLEN];
	int idayofweek = -1, imonth = -1, idayofmonth = -1, iyear = -1;
	int year, remindex;
	int d, m, dow, rm, rd, offset;
	char *ed;
	int retvalsign = 1;

	/*
	 * CONVENTION
	 *
	 * Month:     1-12
	 * Monthname: Jan .. Dec
	 * Day:	      1-31
	 * Weekday:   Mon .. Sun
	 *
	 */

	*flags = 0;

	if (debug)
		debug_determinestyle(1, date, *flags, month, imonth,
		    dayofmonth, idayofmonth, dayofweek, idayofweek,
		    modifieroffset, modifierindex, specialday, syear, iyear);
	if (determinestyle(date, flags, month, &imonth, dayofmonth,
		&idayofmonth, dayofweek, &idayofweek, modifieroffset,
		modifierindex, specialday, syear, &iyear) == 0) {
		if (debug)
			printf("Failed!\n");
		return (0);
	}

	if (debug)
		debug_determinestyle(0, date, *flags, month, imonth,
		    dayofmonth, idayofmonth, dayofweek, idayofweek,
		    modifieroffset, modifierindex, specialday, syear, iyear);

	remindex = 0;
	for (year = year1; year <= year2; year++) {

		int lflags = *flags;
		/* If the year is specified, only do it if it is this year! */
		if ((lflags & F_YEAR) != 0)
			if (iyear != year)
				continue;
		lflags &= ~F_YEAR;

		/* Get important dates for this year */
		yearinfo = years;
		while (yearinfo != NULL) {
			if (yearinfo->year == year)
				break;
			yearinfo = yearinfo -> next;
		}
		if (yearinfo == NULL) {
			yearinfo = (struct yearinfo *)calloc(1,
			    sizeof(struct yearinfo));
			if (yearinfo == NULL)
				errx(1, "Unable to allocate more years");
			yearinfo->year = year;
			yearinfo->next = years;
			years = yearinfo;

			yearinfo->monthdays = monthdaytab[isleap(year)];
			yearinfo->ieaster = easter(year);
			yearinfo->ipaskha = paskha(year);
			fpom(year, UTCOffset, yearinfo->ffullmoon,
			    yearinfo->fnewmoon);
			fpom(year, UTCOFFSET_CNY, yearinfo->ffullmooncny,
			    yearinfo->fnewmooncny);
			fequinoxsolstice(year, UTCOffset,
			    yearinfo->equinoxdays, yearinfo->solsticedays);

			/*
			 * CNY: Match day with sun longitude at 330` with new
			 * moon
			 */
			yearinfo->firstcnyday = calculatesunlongitude30(year,
			    UTCOFFSET_CNY, yearinfo->ichinesemonths);
			for (m = 0; yearinfo->fnewmooncny[m] >= 0; m++) {
				if (yearinfo->fnewmooncny[m] >
				    yearinfo->firstcnyday) {
					yearinfo->firstcnyday =
					    floor(yearinfo->fnewmooncny[m - 1]);
					break;
				}
			}
		}

		/* Same day every year */
		if (lflags == (F_MONTH | F_DAYOFMONTH)) {
			if (!remember_ymd(year, imonth, idayofmonth))
				continue;
			remember(&remindex, yearp, monthp, dayp, edp,
			    year, imonth, idayofmonth, NULL);
			continue;
		}

		/* XXX Same day every year, but variable */
		if (lflags == (F_MONTH | F_DAYOFMONTH | F_VARIABLE)) {
			if (!remember_ymd(year, imonth, idayofmonth))
				continue;
			remember(&remindex, yearp, monthp, dayp, edp,
			    year, imonth, idayofmonth, NULL);
			continue;
		}

		/* Same day every month */
		if (lflags == (F_ALLMONTH | F_DAYOFMONTH)) {
			for (m = 1; m <= 12; m++) {
				if (!remember_ymd(year, m, idayofmonth))
					continue;
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, m, idayofmonth, NULL);
			}
			continue;
		}

		/* Every day of a month */
		if (lflags == (F_ALLDAY | F_MONTH)) {
			for (d = 1; d <= yearinfo->monthdays[imonth]; d++) {
				if (!remember_ymd(year, imonth, d))
					continue;
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, imonth, d, NULL);
			}
			continue;
		}

		/* One day of every month */
		if (lflags == (F_ALLMONTH | F_DAYOFWEEK)) {
			for (m = 1; m <= 12; m++) {
				if (!remember_ymd(year, m, idayofmonth))
					continue;
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, m, idayofmonth, NULL);
			}
			continue;
		}

		/* Every dayofweek of the year */
		if (lflags == (F_DAYOFWEEK | F_VARIABLE)) {
			dow = first_dayofweek_of_year(year);
			if (dow < 0)
				continue;
			d = (idayofweek - dow + 7) % 7 + 1;
			while (d <= 366) {
				if (remember_yd(year, d, &rm, &rd))
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, rm, rd, NULL);
				d += 7;
			}
			continue;
		}

		/*
	         * Every so-manied dayofweek of every month of the year:
	         * Thu-3
	         */
		if (lflags == (F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
			offset = indextooffset(modifierindex);

			for (m = 0; m <= 12; m++) {
	                        d = wdayom (idayofweek, offset, m, year);
				if (remember_ymd(year, m, d)) {
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, m, d, NULL);
					continue;
				}
			}
			continue;
		}

		/*
	         * A certain dayofweek of a month
	         * Jan/Thu-3
	         */
		if (lflags ==
		    (F_MONTH | F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
			offset = indextooffset(modifierindex);
			dow = first_dayofweek_of_month(year, imonth);
			if (dow < 0)
				continue;
			d = (idayofweek - dow + 7) % 7 + 1;

			if (offset > 0) {
				while (d <= yearinfo->monthdays[imonth]) {
					if (--offset == 0
					    && remember_ymd(year, imonth, d)) {
						remember(&remindex,
						    yearp, monthp, dayp, edp,
						    year, imonth, d, NULL);
						continue;
					}
					d += 7;
				}
				continue;
			}
			if (offset < 0) {
				while (d <= yearinfo->monthdays[imonth])
					d += 7;
				while (offset != 0) {
					offset++;
					d -= 7;
				}
				if (remember_ymd(year, imonth, d))
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, imonth, d, NULL);
				continue;
			}
			continue;
		}

		/* Every dayofweek of the month */
		if (lflags == (F_DAYOFWEEK | F_MONTH | F_VARIABLE)) {
			dow = first_dayofweek_of_month(year, imonth);
			if (dow < 0)
				continue;
			d = (idayofweek - dow + 7) % 7 + 1;
			while (d <= yearinfo->monthdays[imonth]) {
				if (remember_ymd(year, imonth, d))
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, imonth, d, NULL);
				d += 7;
			}
			continue;
		}

		/* Easter */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_EASTER)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year, yearinfo->ieaster + offset,
	                        &rm, &rd))
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, NULL);
			continue;
		}

		/* Paskha */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_PASKHA)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year, yearinfo->ipaskha + offset,
	                        &rm, &rd))
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, NULL);
			continue;
		}

		/* Chinese New Year */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_CNY)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year, yearinfo->firstcnyday + offset,
	                        &rm, &rd))
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, NULL);
			continue;
		}

		/* FullMoon */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_FULLMOON)) {
			int i;

			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
				if (remember_yd(year,
	                                floor(yearinfo->ffullmoon[i]) + offset,
					&rm, &rd)) {
					ed = floattotime(
					    yearinfo->ffullmoon[i]);
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, rm, rd, ed);
				}
			}
			continue;
		}

		/* NewMoon */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_NEWMOON)) {
			int i;

			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
				if (remember_yd(year,
					floor(yearinfo->fnewmoon[i]) + offset,
					&rm, &rd)) {
					ed = floattotime(yearinfo->fnewmoon[i]);
					remember(&remindex,
					    yearp, monthp, dayp, edp,
					    year, rm, rd, ed);
				}
			}
			continue;
		}

		/* (Mar|Sep)Equinox */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_MAREQUINOX)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year, yearinfo->equinoxdays[0] + offset,
				&rm, &rd)) {
				ed = floattotime(yearinfo->equinoxdays[0]);
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, ed);
			}
			continue;
		}
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_SEPEQUINOX)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year, yearinfo->equinoxdays[1] + offset,
			    &rm, &rd)) {
				ed = floattotime(yearinfo->equinoxdays[1]);
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, ed);
			}
			continue;
		}

		/* (Jun|Dec)Solstice */
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_JUNSOLSTICE)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year,
				yearinfo->solsticedays[0] + offset, &rm, &rd)) {
				ed = floattotime(yearinfo->solsticedays[0]);
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, ed);
			}
			continue;
		}
		if ((lflags & ~F_MODIFIEROFFSET) ==
		    (F_SPECIALDAY | F_VARIABLE | F_DECSOLSTICE)) {
			offset = 0;
			if ((lflags & F_MODIFIEROFFSET) != 0)
				offset = parseoffset(modifieroffset);
			if (remember_yd(year,
				yearinfo->solsticedays[1] + offset, &rm, &rd)) {
				ed = floattotime(yearinfo->solsticedays[1]);
				remember(&remindex, yearp, monthp, dayp, edp,
				    year, rm, rd, ed);
			}
			continue;
		}

		if (debug) {
			printf("Unprocessed:\n");
			debug_determinestyle(2, date, lflags, month, imonth,
			    dayofmonth, idayofmonth, dayofweek, idayofweek,
			    modifieroffset, modifierindex, specialday, syear,
			    iyear);
		}
		retvalsign = -1;
	}

	if (retvalsign == -1)
		return (-remindex - 1);
	else
		return (remindex);
}

static char *
showflags(int flags)
{
	static char s[SLEN];
	s[0] = '\0';

	if ((flags & F_YEAR) != 0)
		strlcat(s, "year ", SLEN);
	if ((flags & F_MONTH) != 0)
		strlcat(s, "month ", SLEN);
	if ((flags & F_DAYOFWEEK) != 0)
		strlcat(s, "dayofweek ", SLEN);
	if ((flags & F_DAYOFMONTH) != 0)
		strlcat(s, "dayofmonth ", SLEN);
	if ((flags & F_MODIFIERINDEX) != 0)
		strlcat(s, "modifierindex ", SLEN);
	if ((flags & F_MODIFIEROFFSET) != 0)
		strlcat(s, "modifieroffset ", SLEN);
	if ((flags & F_SPECIALDAY) != 0)
		strlcat(s, "specialday ", SLEN);
	if ((flags & F_ALLMONTH) != 0)
		strlcat(s, "allmonth ", SLEN);
	if ((flags & F_ALLDAY) != 0)
		strlcat(s, "allday ", SLEN);
	if ((flags & F_VARIABLE) != 0)
		strlcat(s, "variable ", SLEN);
	if ((flags & F_CNY) != 0)
		strlcat(s, "chinesenewyear ", SLEN);
	if ((flags & F_PASKHA) != 0)
		strlcat(s, "paskha ", SLEN);
	if ((flags & F_EASTER) != 0)
		strlcat(s, "easter ", SLEN);
	if ((flags & F_FULLMOON) != 0)
		strlcat(s, "fullmoon ", SLEN);
	if ((flags & F_NEWMOON) != 0)
		strlcat(s, "newmoon ", SLEN);
	if ((flags & F_MAREQUINOX) != 0)
		strlcat(s, "marequinox ", SLEN);
	if ((flags & F_SEPEQUINOX) != 0)
		strlcat(s, "sepequinox ", SLEN);
	if ((flags & F_JUNSOLSTICE) != 0)
		strlcat(s, "junsolstice ", SLEN);
	if ((flags & F_DECSOLSTICE) != 0)
		strlcat(s, "decsolstice ", SLEN);

	return s;
}

static const char *
getmonthname(int i)
{
	if (i <= 0 || i > 12)
		return ("");
	if (nmonths[i - 1].len != 0 && nmonths[i - 1].name != NULL)
		return (nmonths[i - 1].name);
	return (months[i - 1]);
}

static int
checkmonth(char *s, size_t *len, size_t *offset, const char **month)
{
	struct fixs *n;
	int i;

	for (i = 0; fnmonths[i].name != NULL; i++) {
		n = fnmonths + i;
		if (strncasecmp(s, n->name, n->len) == 0) {
			*len = n->len;
			*month = n->name;
			*offset = i + 1;
			return (1);
		}
	}
	for (i = 0; nmonths[i].name != NULL; i++) {
		n = nmonths + i;
		if (strncasecmp(s, n->name, n->len) == 0) {
			*len = n->len;
			*month = n->name;
			*offset = i + 1;
			return (1);
		}
	}
	for (i = 0; fmonths[i] != NULL; i++) {
		*len = strlen(fmonths[i]);
		if (strncasecmp(s, fmonths[i], *len) == 0) {
			*month = fmonths[i];
			*offset = i + 1;
			return (1);
		}
	}
	for (i = 0; months[i] != NULL; i++) {
		if (strncasecmp(s, months[i], 3) == 0) {
			*len = 3;
			*month = months[i];
			*offset = i + 1;
			return (1);
		}
	}
	return (0);
}

static const char *
getdayofweekname(int i)
{
	if (ndays[i].len != 0 && ndays[i].name != NULL)
		return (ndays[i].name);
	return (days[i]);
}

static int
checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow)
{
	struct fixs *n;
	int i;

	for (i = 0; fndays[i].name != NULL; i++) {
		n = fndays + i;
		if (strncasecmp(s, n->name, n->len) == 0) {
			*len = n->len;
			*dow = n->name;
			*offset = i;
			return (1);
		}
	}
	for (i = 0; ndays[i].name != NULL; i++) {
		n = ndays + i;
		if (strncasecmp(s, n->name, n->len) == 0) {
			*len = n->len;
			*dow = n->name;
			*offset = i;
			return (1);
		}
	}
	for (i = 0; fdays[i] != NULL; i++) {
		*len = strlen(fdays[i]);
		if (strncasecmp(s, fdays[i], *len) == 0) {
			*dow = fdays[i];
			*offset = i;
			return (1);
		}
	}
	for (i = 0; days[i] != NULL; i++) {
		if (strncasecmp(s, days[i], 3) == 0) {
			*len = 3;
			*dow = days[i];
			*offset = i;
			return (1);
		}
	}
	return (0);
}

static int
isonlydigits(char *s, int nostar)
{
	int i;
	for (i = 0; s[i] != '\0'; i++) {
		if (nostar == 0 && s[i] == '*' && s[i + 1] == '\0')
			return 1;
		if (!isdigit((unsigned char)s[i]))
			return (0);
	}
	return (1);
}

static int
indextooffset(char *s)
{
	int i;
	struct fixs *n;
	char *es;

	if (s[0] == '+' || s[0] == '-') {
		i = strtol (s, &es, 10);
		if (*es != '\0')                      /* trailing junk */
			errx (1, "Invalid specifier format: %s\n", s);
		return (i);
	}

	for (i = 0; i < 6; i++) {
		if (strcasecmp(s, sequences[i]) == 0) {
			if (i == 5)
				return (-1);
			return (i + 1);
		}
	}
	for (i = 0; i < 6; i++) {
		n = nsequences + i;
		if (n->len == 0)
			continue;
		if (strncasecmp(s, n->name, n->len) == 0) {
			if (i == 5)
				return (-1);
			return (i + 1);
		}
	}
	return (0);
}

static int
parseoffset(char *s)
{
	return strtol(s, NULL, 10);
}

static char *
floattotime(double f)
{
	static char buf[SLEN];
	int hh, mm, ss, i;

	f -= floor(f);
	i = f * SECSPERDAY;

	hh = i / SECSPERHOUR;
	i %= SECSPERHOUR;
	mm = i / SECSPERMINUTE;
	i %= SECSPERMINUTE;
	ss = i;

	snprintf(buf, SLEN, "%02d:%02d:%02d", hh, mm, ss);
	return (buf);
}

static char *
floattoday(int year, double f)
{
	static char buf[SLEN];
	int i, m, d, hh, mm, ss;
	int *cumdays = cumdaytab[isleap(year)];

	for (i = 0; 1 + cumdays[i] < f; i++)
		;
	m = --i;
	d = floor(f - 1 - cumdays[i]);
	f -= floor(f);
	i = f * SECSPERDAY;

	hh = i / SECSPERHOUR;
	i %= SECSPERHOUR;
	mm = i / SECSPERMINUTE;
	i %= SECSPERMINUTE;
	ss = i;

	snprintf(buf, SLEN, "%02d-%02d %02d:%02d:%02d", m, d, hh, mm, ss);
	return (buf);
}

void
dodebug(char *what)
{
	int year;

	printf("UTCOffset: %g\n", UTCOffset);
	printf("eastlongitude: %d\n", EastLongitude);

	if (strcmp(what, "moon") == 0) {
		double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
		int i;

		for (year = year1; year <= year2; year++) {
			fpom(year, UTCOffset, ffullmoon, fnewmoon);
			printf("Full moon %d:\t", year);
			for (i = 0; ffullmoon[i] >= 0; i++) {
				printf("%g (%s) ", ffullmoon[i],
				    floattoday(year, ffullmoon[i]));
			}
			printf("\nNew moon %d:\t", year);
			for (i = 0; fnewmoon[i] >= 0; i++) {
				printf("%g (%s) ", fnewmoon[i],
				    floattoday(year, fnewmoon[i]));
			}
			printf("\n");

		}

		return;
	}

	if (strcmp(what, "sun") == 0) {
		double equinoxdays[2], solsticedays[2];
		for (year = year1; year <= year2; year++) {
			printf("Sun in %d:\n", year);
			fequinoxsolstice(year, UTCOffset, equinoxdays,
			    solsticedays);
			printf("e[0] - %g (%s)\n",
			    equinoxdays[0],
			    floattoday(year, equinoxdays[0]));
			printf("e[1] - %g (%s)\n",
			    equinoxdays[1],
			    floattoday(year, equinoxdays[1]));
			printf("s[0] - %g (%s)\n",
			    solsticedays[0],
			    floattoday(year, solsticedays[0]));
			printf("s[1] - %g (%s)\n",
			    solsticedays[1],
			    floattoday(year, solsticedays[1]));
		}
		return;
	}
}