1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1992-2009 Edwin Groothuis <edwin@FreeBSD.org>.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30#include <sys/cdefs.h>
31#include <ctype.h>
32#include <math.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <err.h>
37
38#include "calendar.h"
39
40#define	SLEN	100	/* maximum length of date spec. part strings */
41
42static char *showflags(int flags);
43static int isonlydigits(char *s, int nostar);
44static const char *getmonthname(int i);
45static int checkmonth(char *s, size_t *len, size_t *offset, const char **month);
46static const char *getdayofweekname(int i);
47static int checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow);
48static int indextooffset(char *s);
49static int parseoffset(char *s);
50static char *floattoday(int year, double f);
51static char *floattotime(double f);
52static int wdayom (int day, int offset, int month, int year);
53
54/*
55 * Expected styles:
56 *
57 * Date			::=	Month . ' ' . DayOfMonth |
58 *				Month . ' ' . DayOfWeek . ModifierIndex |
59 *				Month . '/' . DayOfMonth |
60 *				Month . '/' . DayOfWeek . ModifierIndex |
61 *				DayOfMonth . ' ' . Month |
62 *				DayOfMonth . '/' . Month |
63 *				DayOfWeek . ModifierIndex . ' ' .Month |
64 *				DayOfWeek . ModifierIndex . '/' .Month |
65 *				DayOfWeek . ModifierIndex |
66 *				SpecialDay . ModifierOffset
67 *
68 * Month		::=	MonthName | MonthNumber | '*'
69 * MonthNumber		::=	'0' ... '9' | '00' ... '09' | '10' ... '12'
70 * MonthName		::=	MonthNameShort | MonthNameLong
71 * MonthNameLong	::=	'January' ... 'December'
72 * MonthNameShort	::=	'Jan' ... 'Dec' | 'Jan.' ... 'Dec.'
73 *
74 * DayOfWeek		::=	DayOfWeekShort | DayOfWeekLong
75 * DayOfWeekShort	::=	'Mon' .. 'Sun'
76 * DayOfWeekLong	::=	'Monday' .. 'Sunday'
77 * DayOfMonth		::=	'0' ... '9' | '00' ... '09' | '10' ... '29' |
78 *				'30' ... '31' | '*'
79 *
80 * ModifierOffset	::=	'' | '+' . ModifierNumber | '-' . ModifierNumber
81 * ModifierNumber	::=	'0' ... '9' | '00' ... '99' | '000' ... '299' |
82 *				'300' ... '359' | '360' ... '365'
83 * ModifierIndex	::=	'Second' | 'Third' | 'Fourth' | 'Fifth' |
84 *				'First' | 'Last'
85 *
86 * SpecialDay		::=	'Easter' | 'Paskha' | 'ChineseNewYear'
87 *
88 */
89static int
90determinestyle(char *date, int *flags,
91    char *month, int *imonth, char *dayofmonth, int *idayofmonth,
92    char *dayofweek, int *idayofweek, char *modifieroffset,
93    char *modifierindex, char *specialday, char *year, int *iyear)
94{
95	char *p, *p1, *p2, *py;
96	const char *dow, *pmonth;
97	char pold;
98	size_t len, offset;
99
100	*flags = F_NONE;
101	*month = '\0';
102	*imonth = 0;
103	*year = '\0';
104	*iyear = 0;
105	*dayofmonth = '\0';
106	*idayofmonth = 0;
107	*dayofweek = '\0';
108	*idayofweek = 0;
109	*modifieroffset = '\0';
110	*modifierindex = '\0';
111	*specialday = '\0';
112
113#define CHECKSPECIAL(s1, s2, lens2, type)				\
114	if (s2 != NULL && strncmp(s1, s2, lens2) == 0) {		\
115		*flags |= F_SPECIALDAY;					\
116		*flags |= type;						\
117		*flags |= F_VARIABLE;					\
118		if (strlen(s1) == lens2) {				\
119			strlcpy(specialday, s1, SLEN);			\
120			return (1);					\
121		}							\
122		strncpy(specialday, s1, lens2);				\
123		specialday[lens2] = '\0';				\
124		strlcpy(modifieroffset, s1 + lens2, SLEN);		\
125		*flags |= F_MODIFIEROFFSET;				\
126		return (1);						\
127	}
128
129	if ((p = strchr(date, ' ')) == NULL) {
130		if ((p = strchr(date, '/')) == NULL) {
131			CHECKSPECIAL(date, STRING_CNY, strlen(STRING_CNY),
132			    F_CNY);
133			CHECKSPECIAL(date, ncny.name, ncny.len, F_CNY);
134			CHECKSPECIAL(date, STRING_NEWMOON,
135			    strlen(STRING_NEWMOON), F_NEWMOON);
136			CHECKSPECIAL(date, nnewmoon.name, nnewmoon.len,
137			    F_NEWMOON);
138			CHECKSPECIAL(date, STRING_FULLMOON,
139			    strlen(STRING_FULLMOON), F_FULLMOON);
140			CHECKSPECIAL(date, nfullmoon.name, nfullmoon.len,
141			    F_FULLMOON);
142			CHECKSPECIAL(date, STRING_PASKHA,
143			    strlen(STRING_PASKHA), F_PASKHA);
144			CHECKSPECIAL(date, npaskha.name, npaskha.len, F_PASKHA);
145			CHECKSPECIAL(date, STRING_EASTER,
146			    strlen(STRING_EASTER), F_EASTER);
147			CHECKSPECIAL(date, neaster.name, neaster.len, F_EASTER);
148			CHECKSPECIAL(date, STRING_MAREQUINOX,
149			    strlen(STRING_MAREQUINOX), F_MAREQUINOX);
150			CHECKSPECIAL(date, nmarequinox.name, nmarequinox.len,
151			    F_SEPEQUINOX);
152			CHECKSPECIAL(date, STRING_SEPEQUINOX,
153			    strlen(STRING_SEPEQUINOX), F_SEPEQUINOX);
154			CHECKSPECIAL(date, nsepequinox.name, nsepequinox.len,
155			    F_SEPEQUINOX);
156			CHECKSPECIAL(date, STRING_JUNSOLSTICE,
157			    strlen(STRING_JUNSOLSTICE), F_JUNSOLSTICE);
158			CHECKSPECIAL(date, njunsolstice.name, njunsolstice.len,
159			    F_JUNSOLSTICE);
160			CHECKSPECIAL(date, STRING_DECSOLSTICE,
161			    strlen(STRING_DECSOLSTICE), F_DECSOLSTICE);
162			CHECKSPECIAL(date, ndecsolstice.name, ndecsolstice.len,
163			    F_DECSOLSTICE);
164			if (checkdayofweek(date, &len, &offset, &dow) != 0) {
165				*flags |= F_DAYOFWEEK;
166				*flags |= F_VARIABLE;
167				*idayofweek = offset;
168				if (strlen(date) == len) {
169					strlcpy(dayofweek, date, SLEN);
170					return (1);
171				}
172				strncpy(dayofweek, date, len);
173				dayofweek[len] = '\0';
174				strlcpy(modifierindex, date + len, SLEN);
175				*flags |= F_MODIFIERINDEX;
176				return (1);
177			}
178			if (isonlydigits(date, 1)) {
179				/* Assume month number only */
180				*flags |= F_MONTH;
181				*imonth = (int)strtol(date, (char **)NULL, 10);
182				strlcpy(month, getmonthname(*imonth), SLEN);
183				return(1);
184			}
185			return (0);
186		}
187	}
188
189	/*
190	 * After this, leave by goto-ing to "allfine" or "fail" to restore the
191	 * original data in `date'.
192	 */
193	pold = *p;
194	*p = 0;
195	p1 = date;
196	p2 = p + 1;
197	/* Now p2 points to the next field and p1 to the first field */
198
199	if ((py = strchr(p2, '/')) != NULL) {
200		/* We have a year in the string. Now this is getting tricky */
201		strlcpy(year, p1, SLEN);
202		*iyear = (int)strtol(year, NULL, 10);
203		p1 = p2;
204		p2 = py + 1;
205		*py = 0;
206		*flags |= F_YEAR;
207	}
208
209	/* Check if there is a month-string in the date */
210	if ((checkmonth(p1, &len, &offset, &pmonth) != 0)
211	    || (checkmonth(p2, &len, &offset, &pmonth) != 0 && (p2 = p1))) {
212		/* p2 is the non-month part */
213		*flags |= F_MONTH;
214		*imonth = offset;
215
216		strlcpy(month, getmonthname(offset), SLEN);
217		if (isonlydigits(p2, 1)) {
218			strlcpy(dayofmonth, p2, SLEN);
219			*idayofmonth = (int)strtol(p2, (char **)NULL, 10);
220			*flags |= F_DAYOFMONTH;
221			goto allfine;
222		}
223		if (strcmp(p2, "*") == 0) {
224			*flags |= F_ALLDAY;
225			goto allfine;
226		}
227
228		if (checkdayofweek(p2, &len, &offset, &dow) != 0) {
229			*flags |= F_DAYOFWEEK;
230			*flags |= F_VARIABLE;
231			*idayofweek = offset;
232			strlcpy(dayofweek, getdayofweekname(offset), SLEN);
233			if (strlen(p2) == len)
234				goto allfine;
235			strlcpy(modifierindex, p2 + len, SLEN);
236			*flags |= F_MODIFIERINDEX;
237			goto allfine;
238		}
239		goto fail;
240	}
241
242	/* Check if there is an every-day or every-month in the string */
243	if ((strcmp(p1, "*") == 0 && isonlydigits(p2, 1))
244	    || (strcmp(p2, "*") == 0 && isonlydigits(p1, 1) && (p2 = p1))) {
245		int d;
246
247		*flags |= F_ALLMONTH;
248		*flags |= F_DAYOFMONTH;
249		d = (int)strtol(p2, (char **)NULL, 10);
250		*idayofmonth = d;
251		snprintf(dayofmonth, SLEN, "%d", d);
252		goto allfine;
253	}
254
255	/* Month as a number, then a weekday */
256	if (isonlydigits(p1, 1)
257	    && checkdayofweek(p2, &len, &offset, &dow) != 0) {
258		int d;
259
260		*flags |= F_MONTH;
261		*flags |= F_DAYOFWEEK;
262		*flags |= F_VARIABLE;
263
264		*idayofweek = offset;
265		d = (int)strtol(p1, (char **)NULL, 10);
266		*imonth = d;
267		strlcpy(month, getmonthname(d), SLEN);
268
269		strlcpy(dayofweek, getdayofweekname(offset), SLEN);
270		if (strlen(p2) == len)
271			goto allfine;
272		strlcpy(modifierindex, p2 + len, SLEN);
273		*flags |= F_MODIFIERINDEX;
274		goto allfine;
275	}
276
277	/* If both the month and date are specified as numbers */
278	if (isonlydigits(p1, 1) && isonlydigits(p2, 0)) {
279		/* Now who wants to be this ambiguous? :-( */
280		int m, d;
281
282		if (strchr(p2, '*') != NULL)
283			*flags |= F_VARIABLE;
284
285		m = (int)strtol(p1, (char **)NULL, 10);
286		d = (int)strtol(p2, (char **)NULL, 10);
287
288		*flags |= F_MONTH;
289		*flags |= F_DAYOFMONTH;
290
291		if (m > 12) {
292			*imonth = d;
293			*idayofmonth = m;
294			strlcpy(month, getmonthname(d), SLEN);
295			snprintf(dayofmonth, SLEN, "%d", m);
296		} else {
297			*imonth = m;
298			*idayofmonth = d;
299			strlcpy(month, getmonthname(m), SLEN);
300			snprintf(dayofmonth, SLEN, "%d", d);
301		}
302		goto allfine;
303	}
304
305	/* FALLTHROUGH */
306fail:
307	*p = pold;
308	return (0);
309allfine:
310	*p = pold;
311	return (1);
312
313}
314
315static void
316remember(int *rememberindex, int *y, int *m, int *d, char **ed, int yy, int mm,
317    int dd, char *extra)
318{
319	static int warned = 0;
320
321	if (*rememberindex >= MAXCOUNT - 1) {
322		if (warned == 0)
323			warnx("Index > %d, ignored", MAXCOUNT);
324		warned++;
325		return;
326	}
327	y[*rememberindex] = yy;
328	m[*rememberindex] = mm;
329	d[*rememberindex] = dd;
330	if (extra != NULL)
331		strlcpy(ed[*rememberindex], extra, SLEN);
332	else
333		ed[*rememberindex][0] = '\0';
334	*rememberindex += 1;
335}
336
337static void
338debug_determinestyle(int dateonly, char *date, int flags, char *month,
339    int imonth, char *dayofmonth, int idayofmonth, char *dayofweek,
340    int idayofweek, char *modifieroffset, char *modifierindex, char *specialday,
341    char *year, int iyear)
342{
343
344	if (dateonly != 0) {
345		printf("-------\ndate: |%s|\n", date);
346		if (dateonly == 1)
347			return;
348	}
349	printf("flags: %x - %s\n", flags, showflags(flags));
350	if (modifieroffset[0] != '\0')
351		printf("modifieroffset: |%s|\n", modifieroffset);
352	if (modifierindex[0] != '\0')
353		printf("modifierindex: |%s|\n", modifierindex);
354	if (year[0] != '\0')
355		printf("year: |%s| (%d)\n", year, iyear);
356	if (month[0] != '\0')
357		printf("month: |%s| (%d)\n", month, imonth);
358	if (dayofmonth[0] != '\0')
359		printf("dayofmonth: |%s| (%d)\n", dayofmonth, idayofmonth);
360	if (dayofweek[0] != '\0')
361		printf("dayofweek: |%s| (%d)\n", dayofweek, idayofweek);
362	if (specialday[0] != '\0')
363		printf("specialday: |%s|\n", specialday);
364}
365
366static struct yearinfo {
367	int year;
368	int ieaster, ipaskha, firstcnyday;
369	double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
370	double ffullmooncny[MAXMOONS], fnewmooncny[MAXMOONS];
371	int ichinesemonths[MAXMOONS];
372	double equinoxdays[2], solsticedays[2];
373	int *monthdays;
374	struct yearinfo *next;
375} *years, *yearinfo;
376
377/*
378 * Calculate dates with offset from weekdays, like Thurs-3, Wed+2, etc.
379 * day is the day of the week,
380 * offset the ordinal number of the weekday in the month.
381 */
382static int
383wdayom (int day, int offset, int month, int year)
384{
385/* Weekday of first day in month */
386	int wday1;                                /* first day of month */
387/* Weekday of last day in month */
388	int wdayn;
389	int d;
390
391	wday1 = first_dayofweek_of_month(year, month);
392	if (wday1 < 0)                          /* not set */
393		return (wday1);
394	/*
395	 * Date of zeroth or first of our weekday in month, depending on the
396	 * relationship with the first of the month.  The range is -6:6.
397	 */
398	d = (day - wday1 + 1) % 7;
399	/*
400	 * Which way are we counting?  Offset 0 is invalid, abs (offset) > 5 is
401	 * meaningless, but that's OK.  Offset 5 may or may not be meaningless,
402	 * so there's no point in complaining for complaining's sake.
403	 */
404	if (offset < 0) {			/* back from end of month */
405						/* FIXME */
406		wdayn = d;
407		while (wdayn <= yearinfo->monthdays[month])
408			wdayn += 7;
409		d = offset * 7 + wdayn;
410	} else if (offset > 0){
411		if (d > 0)
412			d += offset * 7 - 7;
413		else
414			d += offset * 7;
415	} else
416		warnx ("Invalid offset 0");
417	return (d);
418}
419
420/*
421 * Possible date formats include any combination of:
422 *	3-charmonth			(January, Jan, Jan)
423 *	3-charweekday			(Friday, Monday, mon.)
424 *	numeric month or day		(1, 2, 04)
425 *
426 * Any character may separate them, or they may not be separated.  Any line,
427 * following a line that is matched, that starts with "whitespace", is shown
428 * along with the matched line.
429 */
430int
431parsedaymonth(char *date, int *yearp, int *monthp, int *dayp, int *flags,
432    char **edp)
433{
434	char month[SLEN], dayofmonth[SLEN], dayofweek[SLEN], modifieroffset[SLEN];
435	char syear[SLEN];
436	char modifierindex[SLEN], specialday[SLEN];
437	int idayofweek = -1, imonth = -1, idayofmonth = -1, iyear = -1;
438	int year, remindex;
439	int d, m, dow, rm, rd, offset;
440	char *ed;
441	int retvalsign = 1;
442
443	/*
444	 * CONVENTION
445	 *
446	 * Month:     1-12
447	 * Monthname: Jan .. Dec
448	 * Day:	      1-31
449	 * Weekday:   Mon .. Sun
450	 *
451	 */
452
453	*flags = 0;
454
455	if (debug)
456		debug_determinestyle(1, date, *flags, month, imonth,
457		    dayofmonth, idayofmonth, dayofweek, idayofweek,
458		    modifieroffset, modifierindex, specialday, syear, iyear);
459	if (determinestyle(date, flags, month, &imonth, dayofmonth,
460		&idayofmonth, dayofweek, &idayofweek, modifieroffset,
461		modifierindex, specialday, syear, &iyear) == 0) {
462		if (debug)
463			printf("Failed!\n");
464		return (0);
465	}
466
467	if (debug)
468		debug_determinestyle(0, date, *flags, month, imonth,
469		    dayofmonth, idayofmonth, dayofweek, idayofweek,
470		    modifieroffset, modifierindex, specialday, syear, iyear);
471
472	remindex = 0;
473	for (year = year1; year <= year2; year++) {
474
475		int lflags = *flags;
476		/* If the year is specified, only do it if it is this year! */
477		if ((lflags & F_YEAR) != 0)
478			if (iyear != year)
479				continue;
480		lflags &= ~F_YEAR;
481
482		/* Get important dates for this year */
483		yearinfo = years;
484		while (yearinfo != NULL) {
485			if (yearinfo->year == year)
486				break;
487			yearinfo = yearinfo -> next;
488		}
489		if (yearinfo == NULL) {
490			yearinfo = (struct yearinfo *)calloc(1,
491			    sizeof(struct yearinfo));
492			if (yearinfo == NULL)
493				errx(1, "Unable to allocate more years");
494			yearinfo->year = year;
495			yearinfo->next = years;
496			years = yearinfo;
497
498			yearinfo->monthdays = monthdaytab[isleap(year)];
499			yearinfo->ieaster = easter(year);
500			yearinfo->ipaskha = paskha(year);
501			fpom(year, UTCOffset, yearinfo->ffullmoon,
502			    yearinfo->fnewmoon);
503			fpom(year, UTCOFFSET_CNY, yearinfo->ffullmooncny,
504			    yearinfo->fnewmooncny);
505			fequinoxsolstice(year, UTCOffset,
506			    yearinfo->equinoxdays, yearinfo->solsticedays);
507
508			/*
509			 * CNY: Match day with sun longitude at 330` with new
510			 * moon
511			 */
512			yearinfo->firstcnyday = calculatesunlongitude30(year,
513			    UTCOFFSET_CNY, yearinfo->ichinesemonths);
514			for (m = 0; yearinfo->fnewmooncny[m] >= 0; m++) {
515				if (yearinfo->fnewmooncny[m] >
516				    yearinfo->firstcnyday) {
517					yearinfo->firstcnyday =
518					    floor(yearinfo->fnewmooncny[m - 1]);
519					break;
520				}
521			}
522		}
523
524		/* Same day every year */
525		if (lflags == (F_MONTH | F_DAYOFMONTH)) {
526			if (!remember_ymd(year, imonth, idayofmonth))
527				continue;
528			remember(&remindex, yearp, monthp, dayp, edp,
529			    year, imonth, idayofmonth, NULL);
530			continue;
531		}
532
533		/* XXX Same day every year, but variable */
534		if (lflags == (F_MONTH | F_DAYOFMONTH | F_VARIABLE)) {
535			if (!remember_ymd(year, imonth, idayofmonth))
536				continue;
537			remember(&remindex, yearp, monthp, dayp, edp,
538			    year, imonth, idayofmonth, NULL);
539			continue;
540		}
541
542		/* Same day every month */
543		if (lflags == (F_ALLMONTH | F_DAYOFMONTH)) {
544			for (m = 1; m <= 12; m++) {
545				if (!remember_ymd(year, m, idayofmonth))
546					continue;
547				remember(&remindex, yearp, monthp, dayp, edp,
548				    year, m, idayofmonth, NULL);
549			}
550			continue;
551		}
552
553		/* Every day of a month */
554		if (lflags == (F_ALLDAY | F_MONTH)) {
555			for (d = 1; d <= yearinfo->monthdays[imonth]; d++) {
556				if (!remember_ymd(year, imonth, d))
557					continue;
558				remember(&remindex, yearp, monthp, dayp, edp,
559				    year, imonth, d, NULL);
560			}
561			continue;
562		}
563
564		/* One day of every month */
565		if (lflags == (F_ALLMONTH | F_DAYOFWEEK)) {
566			for (m = 1; m <= 12; m++) {
567				if (!remember_ymd(year, m, idayofmonth))
568					continue;
569				remember(&remindex, yearp, monthp, dayp, edp,
570				    year, m, idayofmonth, NULL);
571			}
572			continue;
573		}
574
575		/* Every dayofweek of the year */
576		if (lflags == (F_DAYOFWEEK | F_VARIABLE)) {
577			dow = first_dayofweek_of_year(year);
578			if (dow < 0)
579				continue;
580			d = (idayofweek - dow + 7) % 7 + 1;
581			while (d <= 366) {
582				if (remember_yd(year, d, &rm, &rd))
583					remember(&remindex,
584					    yearp, monthp, dayp, edp,
585					    year, rm, rd, NULL);
586				d += 7;
587			}
588			continue;
589		}
590
591		/*
592	         * Every so-manied dayofweek of every month of the year:
593	         * Thu-3
594	         */
595		if (lflags == (F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
596			offset = indextooffset(modifierindex);
597
598			for (m = 0; m <= 12; m++) {
599	                        d = wdayom (idayofweek, offset, m, year);
600				if (remember_ymd(year, m, d)) {
601					remember(&remindex,
602					    yearp, monthp, dayp, edp,
603					    year, m, d, NULL);
604					continue;
605				}
606			}
607			continue;
608		}
609
610		/*
611	         * A certain dayofweek of a month
612	         * Jan/Thu-3
613	         */
614		if (lflags ==
615		    (F_MONTH | F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
616			offset = indextooffset(modifierindex);
617			dow = first_dayofweek_of_month(year, imonth);
618			if (dow < 0)
619				continue;
620			d = (idayofweek - dow + 7) % 7 + 1;
621
622			if (offset > 0) {
623				while (d <= yearinfo->monthdays[imonth]) {
624					if (--offset == 0
625					    && remember_ymd(year, imonth, d)) {
626						remember(&remindex,
627						    yearp, monthp, dayp, edp,
628						    year, imonth, d, NULL);
629						continue;
630					}
631					d += 7;
632				}
633				continue;
634			}
635			if (offset < 0) {
636				while (d <= yearinfo->monthdays[imonth])
637					d += 7;
638				while (offset != 0) {
639					offset++;
640					d -= 7;
641				}
642				if (remember_ymd(year, imonth, d))
643					remember(&remindex,
644					    yearp, monthp, dayp, edp,
645					    year, imonth, d, NULL);
646				continue;
647			}
648			continue;
649		}
650
651		/* Every dayofweek of the month */
652		if (lflags == (F_DAYOFWEEK | F_MONTH | F_VARIABLE)) {
653			dow = first_dayofweek_of_month(year, imonth);
654			if (dow < 0)
655				continue;
656			d = (idayofweek - dow + 7) % 7 + 1;
657			while (d <= yearinfo->monthdays[imonth]) {
658				if (remember_ymd(year, imonth, d))
659					remember(&remindex,
660					    yearp, monthp, dayp, edp,
661					    year, imonth, d, NULL);
662				d += 7;
663			}
664			continue;
665		}
666
667		/* Easter */
668		if ((lflags & ~F_MODIFIEROFFSET) ==
669		    (F_SPECIALDAY | F_VARIABLE | F_EASTER)) {
670			offset = 0;
671			if ((lflags & F_MODIFIEROFFSET) != 0)
672				offset = parseoffset(modifieroffset);
673			if (remember_yd(year, yearinfo->ieaster + offset,
674	                        &rm, &rd))
675				remember(&remindex, yearp, monthp, dayp, edp,
676				    year, rm, rd, NULL);
677			continue;
678		}
679
680		/* Paskha */
681		if ((lflags & ~F_MODIFIEROFFSET) ==
682		    (F_SPECIALDAY | F_VARIABLE | F_PASKHA)) {
683			offset = 0;
684			if ((lflags & F_MODIFIEROFFSET) != 0)
685				offset = parseoffset(modifieroffset);
686			if (remember_yd(year, yearinfo->ipaskha + offset,
687	                        &rm, &rd))
688				remember(&remindex, yearp, monthp, dayp, edp,
689				    year, rm, rd, NULL);
690			continue;
691		}
692
693		/* Chinese New Year */
694		if ((lflags & ~F_MODIFIEROFFSET) ==
695		    (F_SPECIALDAY | F_VARIABLE | F_CNY)) {
696			offset = 0;
697			if ((lflags & F_MODIFIEROFFSET) != 0)
698				offset = parseoffset(modifieroffset);
699			if (remember_yd(year, yearinfo->firstcnyday + offset,
700	                        &rm, &rd))
701				remember(&remindex, yearp, monthp, dayp, edp,
702				    year, rm, rd, NULL);
703			continue;
704		}
705
706		/* FullMoon */
707		if ((lflags & ~F_MODIFIEROFFSET) ==
708		    (F_SPECIALDAY | F_VARIABLE | F_FULLMOON)) {
709			int i;
710
711			offset = 0;
712			if ((lflags & F_MODIFIEROFFSET) != 0)
713				offset = parseoffset(modifieroffset);
714			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
715				if (remember_yd(year,
716	                                floor(yearinfo->ffullmoon[i]) + offset,
717					&rm, &rd)) {
718					ed = floattotime(
719					    yearinfo->ffullmoon[i]);
720					remember(&remindex,
721					    yearp, monthp, dayp, edp,
722					    year, rm, rd, ed);
723				}
724			}
725			continue;
726		}
727
728		/* NewMoon */
729		if ((lflags & ~F_MODIFIEROFFSET) ==
730		    (F_SPECIALDAY | F_VARIABLE | F_NEWMOON)) {
731			int i;
732
733			offset = 0;
734			if ((lflags & F_MODIFIEROFFSET) != 0)
735				offset = parseoffset(modifieroffset);
736			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
737				if (remember_yd(year,
738					floor(yearinfo->fnewmoon[i]) + offset,
739					&rm, &rd)) {
740					ed = floattotime(yearinfo->fnewmoon[i]);
741					remember(&remindex,
742					    yearp, monthp, dayp, edp,
743					    year, rm, rd, ed);
744				}
745			}
746			continue;
747		}
748
749		/* (Mar|Sep)Equinox */
750		if ((lflags & ~F_MODIFIEROFFSET) ==
751		    (F_SPECIALDAY | F_VARIABLE | F_MAREQUINOX)) {
752			offset = 0;
753			if ((lflags & F_MODIFIEROFFSET) != 0)
754				offset = parseoffset(modifieroffset);
755			if (remember_yd(year, yearinfo->equinoxdays[0] + offset,
756				&rm, &rd)) {
757				ed = floattotime(yearinfo->equinoxdays[0]);
758				remember(&remindex, yearp, monthp, dayp, edp,
759				    year, rm, rd, ed);
760			}
761			continue;
762		}
763		if ((lflags & ~F_MODIFIEROFFSET) ==
764		    (F_SPECIALDAY | F_VARIABLE | F_SEPEQUINOX)) {
765			offset = 0;
766			if ((lflags & F_MODIFIEROFFSET) != 0)
767				offset = parseoffset(modifieroffset);
768			if (remember_yd(year, yearinfo->equinoxdays[1] + offset,
769			    &rm, &rd)) {
770				ed = floattotime(yearinfo->equinoxdays[1]);
771				remember(&remindex, yearp, monthp, dayp, edp,
772				    year, rm, rd, ed);
773			}
774			continue;
775		}
776
777		/* (Jun|Dec)Solstice */
778		if ((lflags & ~F_MODIFIEROFFSET) ==
779		    (F_SPECIALDAY | F_VARIABLE | F_JUNSOLSTICE)) {
780			offset = 0;
781			if ((lflags & F_MODIFIEROFFSET) != 0)
782				offset = parseoffset(modifieroffset);
783			if (remember_yd(year,
784				yearinfo->solsticedays[0] + offset, &rm, &rd)) {
785				ed = floattotime(yearinfo->solsticedays[0]);
786				remember(&remindex, yearp, monthp, dayp, edp,
787				    year, rm, rd, ed);
788			}
789			continue;
790		}
791		if ((lflags & ~F_MODIFIEROFFSET) ==
792		    (F_SPECIALDAY | F_VARIABLE | F_DECSOLSTICE)) {
793			offset = 0;
794			if ((lflags & F_MODIFIEROFFSET) != 0)
795				offset = parseoffset(modifieroffset);
796			if (remember_yd(year,
797				yearinfo->solsticedays[1] + offset, &rm, &rd)) {
798				ed = floattotime(yearinfo->solsticedays[1]);
799				remember(&remindex, yearp, monthp, dayp, edp,
800				    year, rm, rd, ed);
801			}
802			continue;
803		}
804
805		if (debug) {
806			printf("Unprocessed:\n");
807			debug_determinestyle(2, date, lflags, month, imonth,
808			    dayofmonth, idayofmonth, dayofweek, idayofweek,
809			    modifieroffset, modifierindex, specialday, syear,
810			    iyear);
811		}
812		retvalsign = -1;
813	}
814
815	if (retvalsign == -1)
816		return (-remindex - 1);
817	else
818		return (remindex);
819}
820
821static char *
822showflags(int flags)
823{
824	static char s[SLEN];
825	s[0] = '\0';
826
827	if ((flags & F_YEAR) != 0)
828		strlcat(s, "year ", SLEN);
829	if ((flags & F_MONTH) != 0)
830		strlcat(s, "month ", SLEN);
831	if ((flags & F_DAYOFWEEK) != 0)
832		strlcat(s, "dayofweek ", SLEN);
833	if ((flags & F_DAYOFMONTH) != 0)
834		strlcat(s, "dayofmonth ", SLEN);
835	if ((flags & F_MODIFIERINDEX) != 0)
836		strlcat(s, "modifierindex ", SLEN);
837	if ((flags & F_MODIFIEROFFSET) != 0)
838		strlcat(s, "modifieroffset ", SLEN);
839	if ((flags & F_SPECIALDAY) != 0)
840		strlcat(s, "specialday ", SLEN);
841	if ((flags & F_ALLMONTH) != 0)
842		strlcat(s, "allmonth ", SLEN);
843	if ((flags & F_ALLDAY) != 0)
844		strlcat(s, "allday ", SLEN);
845	if ((flags & F_VARIABLE) != 0)
846		strlcat(s, "variable ", SLEN);
847	if ((flags & F_CNY) != 0)
848		strlcat(s, "chinesenewyear ", SLEN);
849	if ((flags & F_PASKHA) != 0)
850		strlcat(s, "paskha ", SLEN);
851	if ((flags & F_EASTER) != 0)
852		strlcat(s, "easter ", SLEN);
853	if ((flags & F_FULLMOON) != 0)
854		strlcat(s, "fullmoon ", SLEN);
855	if ((flags & F_NEWMOON) != 0)
856		strlcat(s, "newmoon ", SLEN);
857	if ((flags & F_MAREQUINOX) != 0)
858		strlcat(s, "marequinox ", SLEN);
859	if ((flags & F_SEPEQUINOX) != 0)
860		strlcat(s, "sepequinox ", SLEN);
861	if ((flags & F_JUNSOLSTICE) != 0)
862		strlcat(s, "junsolstice ", SLEN);
863	if ((flags & F_DECSOLSTICE) != 0)
864		strlcat(s, "decsolstice ", SLEN);
865
866	return s;
867}
868
869static const char *
870getmonthname(int i)
871{
872	if (i <= 0 || i > 12)
873		return ("");
874	if (nmonths[i - 1].len != 0 && nmonths[i - 1].name != NULL)
875		return (nmonths[i - 1].name);
876	return (months[i - 1]);
877}
878
879static int
880checkmonth(char *s, size_t *len, size_t *offset, const char **month)
881{
882	struct fixs *n;
883	int i;
884
885	for (i = 0; fnmonths[i].name != NULL; i++) {
886		n = fnmonths + i;
887		if (strncasecmp(s, n->name, n->len) == 0) {
888			*len = n->len;
889			*month = n->name;
890			*offset = i + 1;
891			return (1);
892		}
893	}
894	for (i = 0; nmonths[i].name != NULL; i++) {
895		n = nmonths + i;
896		if (strncasecmp(s, n->name, n->len) == 0) {
897			*len = n->len;
898			*month = n->name;
899			*offset = i + 1;
900			return (1);
901		}
902	}
903	for (i = 0; fmonths[i] != NULL; i++) {
904		*len = strlen(fmonths[i]);
905		if (strncasecmp(s, fmonths[i], *len) == 0) {
906			*month = fmonths[i];
907			*offset = i + 1;
908			return (1);
909		}
910	}
911	for (i = 0; months[i] != NULL; i++) {
912		if (strncasecmp(s, months[i], 3) == 0) {
913			*len = 3;
914			*month = months[i];
915			*offset = i + 1;
916			return (1);
917		}
918	}
919	return (0);
920}
921
922static const char *
923getdayofweekname(int i)
924{
925	if (ndays[i].len != 0 && ndays[i].name != NULL)
926		return (ndays[i].name);
927	return (days[i]);
928}
929
930static int
931checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow)
932{
933	struct fixs *n;
934	int i;
935
936	for (i = 0; fndays[i].name != NULL; i++) {
937		n = fndays + i;
938		if (strncasecmp(s, n->name, n->len) == 0) {
939			*len = n->len;
940			*dow = n->name;
941			*offset = i;
942			return (1);
943		}
944	}
945	for (i = 0; ndays[i].name != NULL; i++) {
946		n = ndays + i;
947		if (strncasecmp(s, n->name, n->len) == 0) {
948			*len = n->len;
949			*dow = n->name;
950			*offset = i;
951			return (1);
952		}
953	}
954	for (i = 0; fdays[i] != NULL; i++) {
955		*len = strlen(fdays[i]);
956		if (strncasecmp(s, fdays[i], *len) == 0) {
957			*dow = fdays[i];
958			*offset = i;
959			return (1);
960		}
961	}
962	for (i = 0; days[i] != NULL; i++) {
963		if (strncasecmp(s, days[i], 3) == 0) {
964			*len = 3;
965			*dow = days[i];
966			*offset = i;
967			return (1);
968		}
969	}
970	return (0);
971}
972
973static int
974isonlydigits(char *s, int nostar)
975{
976	int i;
977	for (i = 0; s[i] != '\0'; i++) {
978		if (nostar == 0 && s[i] == '*' && s[i + 1] == '\0')
979			return 1;
980		if (!isdigit((unsigned char)s[i]))
981			return (0);
982	}
983	return (1);
984}
985
986static int
987indextooffset(char *s)
988{
989	int i;
990	struct fixs *n;
991	char *es;
992
993	if (s[0] == '+' || s[0] == '-') {
994		i = strtol (s, &es, 10);
995		if (*es != '\0')                      /* trailing junk */
996			errx (1, "Invalid specifier format: %s\n", s);
997		return (i);
998	}
999
1000	for (i = 0; i < 6; i++) {
1001		if (strcasecmp(s, sequences[i]) == 0) {
1002			if (i == 5)
1003				return (-1);
1004			return (i + 1);
1005		}
1006	}
1007	for (i = 0; i < 6; i++) {
1008		n = nsequences + i;
1009		if (n->len == 0)
1010			continue;
1011		if (strncasecmp(s, n->name, n->len) == 0) {
1012			if (i == 5)
1013				return (-1);
1014			return (i + 1);
1015		}
1016	}
1017	return (0);
1018}
1019
1020static int
1021parseoffset(char *s)
1022{
1023	return strtol(s, NULL, 10);
1024}
1025
1026static char *
1027floattotime(double f)
1028{
1029	static char buf[SLEN];
1030	int hh, mm, ss, i;
1031
1032	f -= floor(f);
1033	i = f * SECSPERDAY;
1034
1035	hh = i / SECSPERHOUR;
1036	i %= SECSPERHOUR;
1037	mm = i / SECSPERMINUTE;
1038	i %= SECSPERMINUTE;
1039	ss = i;
1040
1041	snprintf(buf, SLEN, "%02d:%02d:%02d", hh, mm, ss);
1042	return (buf);
1043}
1044
1045static char *
1046floattoday(int year, double f)
1047{
1048	static char buf[SLEN];
1049	int i, m, d, hh, mm, ss;
1050	int *cumdays = cumdaytab[isleap(year)];
1051
1052	for (i = 0; 1 + cumdays[i] < f; i++)
1053		;
1054	m = --i;
1055	d = floor(f - 1 - cumdays[i]);
1056	f -= floor(f);
1057	i = f * SECSPERDAY;
1058
1059	hh = i / SECSPERHOUR;
1060	i %= SECSPERHOUR;
1061	mm = i / SECSPERMINUTE;
1062	i %= SECSPERMINUTE;
1063	ss = i;
1064
1065	snprintf(buf, SLEN, "%02d-%02d %02d:%02d:%02d", m, d, hh, mm, ss);
1066	return (buf);
1067}
1068
1069void
1070dodebug(char *what)
1071{
1072	int year;
1073
1074	printf("UTCOffset: %g\n", UTCOffset);
1075	printf("eastlongitude: %d\n", EastLongitude);
1076
1077	if (strcmp(what, "moon") == 0) {
1078		double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
1079		int i;
1080
1081		for (year = year1; year <= year2; year++) {
1082			fpom(year, UTCOffset, ffullmoon, fnewmoon);
1083			printf("Full moon %d:\t", year);
1084			for (i = 0; ffullmoon[i] >= 0; i++) {
1085				printf("%g (%s) ", ffullmoon[i],
1086				    floattoday(year, ffullmoon[i]));
1087			}
1088			printf("\nNew moon %d:\t", year);
1089			for (i = 0; fnewmoon[i] >= 0; i++) {
1090				printf("%g (%s) ", fnewmoon[i],
1091				    floattoday(year, fnewmoon[i]));
1092			}
1093			printf("\n");
1094
1095		}
1096
1097		return;
1098	}
1099
1100	if (strcmp(what, "sun") == 0) {
1101		double equinoxdays[2], solsticedays[2];
1102		for (year = year1; year <= year2; year++) {
1103			printf("Sun in %d:\n", year);
1104			fequinoxsolstice(year, UTCOffset, equinoxdays,
1105			    solsticedays);
1106			printf("e[0] - %g (%s)\n",
1107			    equinoxdays[0],
1108			    floattoday(year, equinoxdays[0]));
1109			printf("e[1] - %g (%s)\n",
1110			    equinoxdays[1],
1111			    floattoday(year, equinoxdays[1]));
1112			printf("s[0] - %g (%s)\n",
1113			    solsticedays[0],
1114			    floattoday(year, solsticedays[0]));
1115			printf("s[1] - %g (%s)\n",
1116			    solsticedays[1],
1117			    floattoday(year, solsticedays[1]));
1118		}
1119		return;
1120	}
1121}
1122