1 /* $OpenBSD: day.c,v 1.18 2004/12/10 20:47:30 mickey Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1993, 1994
5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __COPYRIGHT("@(#) Copyright (c) 1989, 1993\n\
34 The Regents of the University of California. All rights reserved.\n");
35 __SCCSID("@(#)calendar.c 8.3 (Berkeley) 3/25/94");
36 __RCSID("$MirOS: src/usr.bin/calendar/day.c,v 1.3 2010/09/21 21:24:33 tg Exp $");
37
38 #include <sys/types.h>
39 #include <sys/uio.h>
40
41 #include <ctype.h>
42 #include <err.h>
43 #include <locale.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <time.h>
48 #include <tzfile.h>
49
50 #include "pathnames.h"
51 #include "calendar.h"
52
53 #define WEEKLY 1
54 #define MONTHLY 2
55 #define YEARLY 3
56
57 struct tm *tp;
58 int *cumdays, offset;
59 char dayname[10];
60 enum calendars calendar;
61 u_long julian;
62
63
64 /* 1-based month, 0-based days, cumulative */
65 int daytab[][14] = {
66 { 0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 },
67 { 0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
68 };
69
70 static char *days[] = {
71 "sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
72 };
73
74 static char *months[] = {
75 "jan", "feb", "mar", "apr", "may", "jun",
76 "jul", "aug", "sep", "oct", "nov", "dec", NULL,
77 };
78
79 static struct fixs fndays[8]; /* full national days names */
80 static struct fixs ndays[8]; /* short national days names */
81
82 static struct fixs fnmonths[13]; /* full national months names */
83 static struct fixs nmonths[13]; /* short national month names */
84
85
setnnames(void)86 void setnnames(void)
87 {
88 char buf[80];
89 int i, l;
90 struct tm tm;
91
92 for (i = 0; i < 7; i++) {
93 tm.tm_wday = i;
94 l = strftime(buf, sizeof(buf), "%a", &tm);
95 for (; l > 0 && isspace((int)buf[l - 1]); l--)
96 ;
97 buf[l] = '\0';
98 if (ndays[i].name != NULL)
99 free(ndays[i].name);
100 if ((ndays[i].name = strdup(buf)) == NULL)
101 err(1, NULL);
102 ndays[i].len = strlen(buf);
103
104 l = strftime(buf, sizeof(buf), "%A", &tm);
105 for (; l > 0 && isspace((int)buf[l - 1]); l--)
106 ;
107 buf[l] = '\0';
108 if (fndays[i].name != NULL)
109 free(fndays[i].name);
110 if ((fndays[i].name = strdup(buf)) == NULL)
111 err(1, NULL);
112 fndays[i].len = strlen(buf);
113 }
114
115 for (i = 0; i < 12; i++) {
116 tm.tm_mon = i;
117 l = strftime(buf, sizeof(buf), "%b", &tm);
118 for (; l > 0 && isspace((int)buf[l - 1]); l--)
119 ;
120 buf[l] = '\0';
121 if (nmonths[i].name != NULL)
122 free(nmonths[i].name);
123 if ((nmonths[i].name = strdup(buf)) == NULL)
124 err(1, NULL);
125 nmonths[i].len = strlen(buf);
126
127 l = strftime(buf, sizeof(buf), "%B", &tm);
128 for (; l > 0 && isspace((int)buf[l - 1]); l--)
129 ;
130 buf[l] = '\0';
131 if (fnmonths[i].name != NULL)
132 free(fnmonths[i].name);
133 if ((fnmonths[i].name = strdup(buf)) == NULL)
134 err(1, NULL);
135 fnmonths[i].len = strlen(buf);
136 }
137 /* Hardwired special events */
138 spev[0].name = strdup(PESACH);
139 spev[0].nlen = PESACHLEN;
140 spev[0].getev = pesach;
141 spev[1].name = strdup(EASTER);
142 spev[1].nlen = EASTERNAMELEN;
143 spev[1].getev = easter;
144 spev[2].name = strdup(PASKHA);
145 spev[2].nlen = PASKHALEN;
146 spev[2].getev = paskha;
147 for (i = 0; i < NUMEV; i++) {
148 if (spev[i].name == NULL)
149 err(1, NULL);
150 spev[i].uname = NULL;
151 }
152 }
153
154 void
settime(now)155 settime(now)
156 time_t *now;
157 {
158 tp = localtime(now);
159 tp->tm_sec = 0;
160 tp->tm_min = 0;
161 /* Avoid getting caught by a timezone shift; set time to noon */
162 tp->tm_isdst = 0;
163 tp->tm_hour = 12;
164 *now = mktime(tp);
165 if (isleap(tp->tm_year + TM_YEAR_BASE))
166 cumdays = daytab[1];
167 else
168 cumdays = daytab[0];
169 /* Friday displays Monday's events */
170 offset = tp->tm_wday == 5 ? 3 : 1;
171 if (f_dayAfter)
172 offset = 0; /* Except not when range is set explicitly */
173 header[5].iov_base = dayname;
174
175 #ifndef __MirBSD__
176 (void) setlocale(LC_TIME, "C");
177 #endif
178 header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
179 #ifndef __MirBSD__
180 (void) setlocale(LC_TIME, "");
181 #endif
182
183 setnnames();
184 }
185
186 /* convert [Year][Month]Day into unix time (since 1970)
187 * Year: two or four digits, Month: two digits, Day: two digits
188 */
Mktime(date)189 time_t Mktime (date)
190 char *date;
191 {
192 time_t t;
193 int len;
194 struct tm tm;
195
196 (void)time(&t);
197 tp = localtime(&t);
198
199 len = strlen(date);
200 if (len < 2)
201 return((time_t)-1);
202 tm.tm_sec = 0;
203 tm.tm_min = 0;
204 /* Avoid getting caught by a timezone shift; set time to noon */
205 tm.tm_isdst = 0;
206 tm.tm_hour = 12;
207 tm.tm_wday = 0;
208 tm.tm_mday = tp->tm_mday;
209 tm.tm_mon = tp->tm_mon;
210 tm.tm_year = tp->tm_year;
211
212 /* Day */
213 tm.tm_mday = atoi(date + len - 2);
214
215 /* Month */
216 if (len >= 4) {
217 *(date + len - 2) = '\0';
218 tm.tm_mon = atoi(date + len - 4) - 1;
219 }
220
221 /* Year */
222 if (len >= 6) {
223 *(date + len - 4) = '\0';
224 tm.tm_year = atoi(date);
225
226 /* tm_year up TM_YEAR_BASE ... */
227 if (tm.tm_year < 69) /* Y2K */
228 tm.tm_year += 2000 - TM_YEAR_BASE;
229 else if (tm.tm_year < 100)
230 tm.tm_year += 1900 - TM_YEAR_BASE;
231 else if (tm.tm_year > TM_YEAR_BASE)
232 tm.tm_year -= TM_YEAR_BASE;
233 }
234
235 #if DEBUG
236 printf("Mktime: %d %d %d %s\n", (int)mktime(&tm), (int)t, len,
237 asctime(&tm));
238 #endif
239 return(mktime(&tm));
240 }
241
242 void
adjust_calendar(int * day,int * month)243 adjust_calendar(int *day, int *month)
244 {
245 switch (calendar) {
246 case GREGORIAN:
247 break;
248
249 case JULIAN:
250 *day += julian;
251 if (*day > (cumdays[*month + 1] - cumdays[*month])) {
252 *day -= (cumdays[*month + 1] - cumdays[*month]);
253 if (++*month > 12)
254 *month = 1;
255 }
256 break;
257 case LUNAR:
258 break;
259 }
260 }
261
262 /*
263 * Possible date formats include any combination of:
264 * 3-charmonth (January, Jan, Jan)
265 * 3-charweekday (Friday, Monday, mon.)
266 * numeric month or day (1, 2, 04)
267 *
268 * Any character except \t or '*' may separate them, or they may not be
269 * separated. Any line following a line that is matched, that starts
270 * with \t, is shown along with the matched line.
271 */
272 struct match *
isnow(endp,bodun)273 isnow(endp, bodun)
274 char *endp;
275 int bodun;
276 {
277 int day = 0, flags = 0, month = 0, v1, v2, i;
278 int monthp, dayp, varp = 0;
279 struct match *matches = NULL, *tmp, *tmp2;
280 int interval = YEARLY; /* how frequently the event repeats. */
281 int vwd = 0; /* Variable weekday */
282 time_t tdiff, ttmp;
283 struct tm tmtmp;
284
285 /*
286 * CONVENTION
287 *
288 * Month: 1-12
289 * Monthname: Jan .. Dec
290 * Day: 1-31
291 * Weekday: Mon-Sun
292 *
293 */
294
295 /* read first field */
296 /* didn't recognize anything, skip it */
297 if (!(v1 = getfield(endp, &endp, &flags)))
298 return (NULL);
299
300 /* adjust bodun rate */
301 if (bodun && !bodun_always)
302 bodun = !arc4random_uniform(3);
303
304 /* Easter or Easter depending days */
305 if (flags & F_SPECIAL)
306 vwd = v1;
307
308 /*
309 * 1. {Weekday,Day} XYZ ...
310 *
311 * where Day is > 12
312 */
313 else if (flags & F_ISDAY || v1 > 12) {
314
315 /* found a day; day: 13-31 or weekday: 1-7 */
316 day = v1;
317
318 /* {Day,Weekday} {Month,Monthname} ... */
319 /* if no recognizable month, assume just a day alone -- this is
320 * very unlikely and can only happen after the first 12 days.
321 * --find month or use current month */
322 if (!(month = getfield(endp, &endp, &flags))) {
323 month = tp->tm_mon + 1;
324 /* F_ISDAY is set only if a weekday was spelled out */
325 /* F_ISDAY must be set if 0 < day < 8 */
326 if ((day <= 7) && (day >= 1))
327 interval = WEEKLY;
328 else
329 interval = MONTHLY;
330 } else if ((day <= 7) && (day >= 1))
331 day += 10;
332 /* it's a weekday; make it the first one of the month */
333 if (month == -1) {
334 month = tp->tm_mon + 1;
335 interval = MONTHLY;
336 } else if (calendar)
337 adjust_calendar(&day, &month);
338 if ((month > 12) || (month < 1))
339 return (NULL);
340 }
341
342 /* 2. {Monthname} XYZ ... */
343 else if (flags & F_ISMONTH) {
344 month = v1;
345 if (month == -1) {
346 month = tp->tm_mon + 1;
347 interval = MONTHLY;
348 }
349 /* Monthname {day,weekday} */
350 /* if no recognizable day, assume the first day in month */
351 if (!(day = getfield(endp, &endp, &flags)))
352 day = 1;
353 /* If a weekday was spelled out without an ordering,
354 * assume the first of that day in the month */
355 if ((flags & F_ISDAY)) {
356 if ((day >= 1) && (day <=7))
357 day += 10;
358 } else if (calendar)
359 adjust_calendar(&day, &month);
360 }
361
362 /* Hm ... */
363 else {
364 v2 = getfield(endp, &endp, &flags);
365
366 /*
367 * {Day} {Monthname} ...
368 * where Day <= 12
369 */
370 if (flags & F_ISMONTH) {
371 day = v1;
372 month = v2;
373 if (month == -1) {
374 month = tp->tm_mon + 1;
375 interval = MONTHLY;
376 } else if (calendar)
377 adjust_calendar(&day, &month);
378 }
379
380 /* {Month} {Weekday,Day} ... */
381 else {
382 /* F_ISDAY set, v2 > 12, or no way to tell */
383 month = v1;
384 /* if no recognizable day, assume the first */
385 day = v2 ? v2 : 1;
386 if ((flags & F_ISDAY)) {
387 if ((day >= 1) && (day <= 7))
388 day += 10;
389 } else
390 adjust_calendar(&day, &month);
391 }
392 }
393
394 /* convert Weekday into *next* Day,
395 * e.g.: 'Sunday' -> 22
396 * 'SundayLast' -> ??
397 */
398 if (flags & F_ISDAY) {
399 #if DEBUG
400 fprintf(stderr, "\nday: %d %s month %d\n", day, endp, month);
401 #endif
402
403 varp = 1;
404 /* variable weekday, SundayLast, MondayFirst ... */
405 if (day < 0 || day >= 10)
406 vwd = day;
407 else {
408 day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
409 interval = WEEKLY;
410 }
411 } else
412 /* Check for silliness. Note we still catch Feb 29 */
413 if (!(flags & F_SPECIAL) &&
414 (day > (cumdays[month + 1] - cumdays[month]) || day < 1)) {
415 if (!((month == 2 && day == 29) ||
416 (interval == MONTHLY && day <= 31)))
417 return (NULL);
418 }
419
420 if (!(flags & F_SPECIAL)) {
421 monthp = month;
422 dayp = day;
423 day = cumdays[month] + day;
424 #if DEBUG
425 fprintf(stderr, "day2: day %d(%d) yday %d\n", dayp, day, tp->tm_yday);
426 #endif
427 /* Speed up processing for the most common situation: yearly events
428 * when the interval being checked is less than a month or so (this
429 * could be less than a year, but then we have to start worrying about
430 * leap years). Only one event can match, and it's easy to find.
431 * Note we can't check special events, because they can wander widely.
432 */
433 if (((v1 = offset + f_dayAfter) < 50) && (interval == YEARLY)) {
434 memcpy(&tmtmp, tp, sizeof(struct tm));
435 tmtmp.tm_mday = dayp;
436 tmtmp.tm_mon = monthp - 1;
437 if (vwd) {
438 /* We want the event next year if it's late now
439 * this year. The 50-day limit means we don't have to
440 * worry if next year is or isn't a leap year.
441 */
442 if (tp->tm_yday > 300 && tmtmp.tm_mon <= 1)
443 variable_weekday(&vwd, tmtmp.tm_mon + 1,
444 tmtmp.tm_year + TM_YEAR_BASE + 1);
445 else
446 variable_weekday(&vwd, tmtmp.tm_mon + 1,
447 tmtmp.tm_year + TM_YEAR_BASE);
448 day = cumdays[tmtmp.tm_mon + 1] + vwd;
449 tmtmp.tm_mday = vwd;
450 }
451 v2 = day - tp->tm_yday;
452 if ((v2 > v1) || (v2 < 0)) {
453 if ((v2 += isleap(tp->tm_year + TM_YEAR_BASE) ? 366 : 365)
454 <= v1)
455 tmtmp.tm_year++;
456 else if(!bodun || (day - tp->tm_yday) != -1)
457 return(NULL);
458 }
459 if ((tmp = malloc(sizeof(struct match))) == NULL)
460 err(1, NULL);
461
462 if (bodun && (day - tp->tm_yday) == -1) {
463 tmp->when = f_time - 1 * SECSPERDAY;
464 tmtmp.tm_mday++;
465 tmp->bodun = 1;
466 } else {
467 tmp->when = f_time + v2 * SECSPERDAY;
468 tmp->bodun = 0;
469 }
470
471 (void)mktime(&tmtmp);
472 if (strftime(tmp->print_date,
473 sizeof(tmp->print_date),
474 /* "%a %b %d", &tm); Skip weekdays */
475 "%b %d", &tmtmp) == 0)
476 tmp->print_date[sizeof(tmp->print_date) - 1] = '\0';
477
478 tmp->var = varp;
479 tmp->next = NULL;
480 return(tmp);
481 }
482 } else {
483 varp = 1;
484 /* Set up v1 to the event number and ... */
485 v1 = vwd % (NUMEV + 1) - 1;
486 vwd /= (NUMEV + 1);
487 if (v1 < 0) {
488 v1 += NUMEV + 1;
489 vwd--;
490 }
491 dayp = monthp = 1; /* Why not */
492 }
493
494 /* Compare to past and coming instances of the event. The i == 0 part
495 * of the loop corresponds to this specific instance. Note that we
496 * can leave things sort of higgledy-piggledy since a mktime() happens
497 * on this before anything gets printed. Also note that even though
498 * we've effectively gotten rid of f_dayBefore, we still have to check
499 * the one prior event for situations like "the 31st of every month"
500 * and "yearly" events which could happen twice in one year but not in
501 * the next */
502 tmp2 = matches;
503 for (i = -1; i < 2; i++) {
504 memcpy(&tmtmp, tp, sizeof(struct tm));
505 tmtmp.tm_mday = dayp;
506 tmtmp.tm_mon = month = monthp - 1;
507 do {
508 v2 = 0;
509 switch (interval) {
510 case WEEKLY:
511 tmtmp.tm_mday += 7 * i;
512 break;
513 case MONTHLY:
514 month += i;
515 tmtmp.tm_mon = month;
516 switch(tmtmp.tm_mon) {
517 case -1:
518 tmtmp.tm_mon = month = 11;
519 tmtmp.tm_year--;
520 break;
521 case 12:
522 tmtmp.tm_mon = month = 0;
523 tmtmp.tm_year++;
524 break;
525 }
526 if (vwd) {
527 v1 = vwd;
528 variable_weekday(&v1, tmtmp.tm_mon + 1,
529 tmtmp.tm_year + TM_YEAR_BASE);
530 tmtmp.tm_mday = v1;
531 } else
532 tmtmp.tm_mday = dayp;
533 break;
534 case YEARLY:
535 default:
536 tmtmp.tm_year += i;
537 if (flags & F_SPECIAL) {
538 tmtmp.tm_mon = 0; /* Gee, mktime() is nice */
539 tmtmp.tm_mday = spev[v1].getev(tmtmp.tm_year +
540 TM_YEAR_BASE) + vwd;
541 } else if (vwd) {
542 v1 = vwd;
543 variable_weekday(&v1, tmtmp.tm_mon + 1,
544 tmtmp.tm_year + TM_YEAR_BASE);
545 tmtmp.tm_mday = v1;
546 } else {
547 /* Need the following to keep Feb 29 from
548 * becoming Mar 1 */
549 tmtmp.tm_mday = dayp;
550 tmtmp.tm_mon = monthp - 1;
551 }
552 break;
553 }
554 /* How many days apart are we */
555 if ((ttmp = mktime(&tmtmp)) == -1)
556 warnx("time out of range: %s", endp);
557 else {
558 tdiff = difftime(ttmp, f_time)/ SECSPERDAY;
559 if (tdiff <= offset + f_dayAfter ||
560 (bodun && tdiff == -1)) {
561 if (tdiff >= 0 ||
562 (bodun && tdiff == -1)) {
563 if ((tmp = malloc(sizeof(struct match))) == NULL)
564 err(1, NULL);
565 tmp->when = ttmp;
566 if (strftime(tmp->print_date,
567 sizeof(tmp->print_date),
568 /* "%a %b %d", &tm); Skip weekdays */
569 "%b %d", &tmtmp) == 0)
570 tmp->print_date[sizeof(tmp->print_date) - 1] = '\0';
571 tmp->bodun = bodun && tdiff == -1;
572 tmp->var = varp;
573 tmp->next = NULL;
574 if (tmp2)
575 tmp2->next = tmp;
576 else
577 matches = tmp;
578 tmp2 = tmp;
579 v2 = (i == 1) ? 1 : 0;
580 }
581 } else
582 i = 2; /* No point checking in the future */
583 }
584 } while (v2 != 0);
585 }
586 return (matches);
587 }
588
589
590 int
getmonth(s)591 getmonth(s)
592 char *s;
593 {
594 char **p;
595 struct fixs *n;
596
597 for (n = fnmonths; n->name; ++n)
598 if (!strncasecmp(s, n->name, n->len))
599 return ((n - fnmonths) + 1);
600 for (n = nmonths; n->name; ++n)
601 if (!strncasecmp(s, n->name, n->len))
602 return ((n - nmonths) + 1);
603 for (p = months; *p; ++p)
604 if (!strncasecmp(s, *p, 3))
605 return ((p - months) + 1);
606 return (0);
607 }
608
609
610 int
getday(s)611 getday(s)
612 char *s;
613 {
614 char **p;
615 struct fixs *n;
616
617 for (n = fndays; n->name; ++n)
618 if (!strncasecmp(s, n->name, n->len))
619 return ((n - fndays) + 1);
620 for (n = ndays; n->name; ++n)
621 if (!strncasecmp(s, n->name, n->len))
622 return ((n - ndays) + 1);
623 for (p = days; *p; ++p)
624 if (!strncasecmp(s, *p, 3))
625 return ((p - days) + 1);
626 return (0);
627 }
628
629 /* return offset for variable weekdays
630 * -1 -> last weekday in month
631 * +1 -> first weekday in month
632 * ... etc ...
633 */
634 int
getdayvar(s)635 getdayvar(s)
636 char *s;
637 {
638 int offset;
639
640
641 offset = strlen(s);
642
643 /* Sun+1 or Wednesday-2
644 * ^ ^ */
645
646 /* printf ("x: %s %s %d\n", s, s + offset - 2, offset); */
647 switch(*(s + offset - 2)) {
648 case '-':
649 case '+':
650 return(atoi(s + offset - 2));
651 break;
652 }
653
654 /*
655 * some aliases: last, first, second, third, fourth
656 */
657
658 /* last */
659 if (offset > 4 && !strcasecmp(s + offset - 4, "last"))
660 return(-1);
661 else if (offset > 5 && !strcasecmp(s + offset - 5, "first"))
662 return(+1);
663 else if (offset > 6 && !strcasecmp(s + offset - 6, "second"))
664 return(+2);
665 else if (offset > 5 && !strcasecmp(s + offset - 5, "third"))
666 return(+3);
667 else if (offset > 6 && !strcasecmp(s + offset - 6, "fourth"))
668 return(+4);
669
670 /* no offset detected */
671 return(0);
672 }
673
674
675 int
foy(year)676 foy(year)
677 int year;
678 {
679 /* 0-6; what weekday Jan 1 is */
680 year--;
681 return ((1 - year/100 + year/400 + (int)(365.25 * year)) % 7);
682 }
683
684
685
686 void
variable_weekday(day,month,year)687 variable_weekday(day, month, year)
688 int *day, month, year;
689 {
690 int v1, v2;
691 int *cumdays;
692 int day1;
693
694 if (isleap(year))
695 cumdays = daytab[1];
696 else
697 cumdays = daytab[0];
698 day1 = foy(year);
699 /* negative offset; last, -4 .. -1 */
700 if (*day < 0) {
701 v1 = *day/10 - 1; /* offset -4 ... -1 */
702 *day = 10 + (*day % 10); /* day 1 ... 7 */
703
704 /* which weekday the end of the month is (1-7) */
705 v2 = (cumdays[month + 1] + day1) % 7 + 1;
706
707 /* and subtract enough days */
708 *day = cumdays[month + 1] - cumdays[month] +
709 (v1 + 1) * 7 - (v2 - *day + 7) % 7;
710 #if DEBUG
711 fprintf(stderr, "\nMonth %d ends on weekday %d\n", month, v2);
712 #endif
713 }
714
715 /* first, second ... +1 ... +5 */
716 else {
717 v1 = *day/10; /* offset */
718 *day = *day % 10;
719
720 /* which weekday the first of the month is (1-7) */
721 v2 = (cumdays[month] + 1 + day1) % 7 + 1;
722
723 /* and add enough days */
724 *day = 1 + (v1 - 1) * 7 + (*day - v2 + 7) % 7;
725 #if DEBUG
726 fprintf(stderr, "\nMonth %d starts on weekday %d\n", month, v2);
727 #endif
728 }
729 }
730