xref: /netbsd-src/lib/libc/time/zdump.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: zdump.c,v 1.17 2009/12/31 22:49:16 mlelstv Exp $	*/
2 /*
3 ** This file is in the public domain, so clarified as of
4 ** 2009-05-17 by Arthur David Olson.
5 */
6 
7 #include <sys/cdefs.h>
8 #ifndef lint
9 #ifndef NOID
10 __RCSID("$NetBSD: zdump.c,v 1.17 2009/12/31 22:49:16 mlelstv Exp $");
11 #endif /* !defined NOID */
12 #endif /* !defined lint */
13 
14 static char	elsieid[] = "@(#)zdump.c	8.9";
15 
16 /*
17 ** This code has been made independent of the rest of the time
18 ** conversion package to increase confidence in the verification it provides.
19 ** You can use this code to help in verifying other implementations.
20 */
21 
22 #include "stdio.h"	/* for stdout, stderr */
23 #include "string.h"	/* for strcpy */
24 #include "sys/types.h"	/* for time_t */
25 #include "time.h"	/* for struct tm */
26 #include "stdlib.h"	/* for exit, malloc, atoi */
27 #include <err.h>
28 #include "float.h"	/* for FLT_MAX and DBL_MAX */
29 #include "ctype.h"	/* for isalpha et al. */
30 #ifndef isascii
31 #define isascii(x) 1
32 #endif /* !defined isascii */
33 
34 #ifndef ZDUMP_LO_YEAR
35 #define ZDUMP_LO_YEAR	(-500)
36 #endif /* !defined ZDUMP_LO_YEAR */
37 
38 #ifndef ZDUMP_HI_YEAR
39 #define ZDUMP_HI_YEAR	2500
40 #endif /* !defined ZDUMP_HI_YEAR */
41 
42 #ifndef MAX_STRING_LENGTH
43 #define MAX_STRING_LENGTH	1024
44 #endif /* !defined MAX_STRING_LENGTH */
45 
46 #ifndef TRUE
47 #define TRUE		1
48 #endif /* !defined TRUE */
49 
50 #ifndef FALSE
51 #define FALSE		0
52 #endif /* !defined FALSE */
53 
54 #ifndef EXIT_SUCCESS
55 #define EXIT_SUCCESS	0
56 #endif /* !defined EXIT_SUCCESS */
57 
58 #ifndef EXIT_FAILURE
59 #define EXIT_FAILURE	1
60 #endif /* !defined EXIT_FAILURE */
61 
62 #ifndef SECSPERMIN
63 #define SECSPERMIN	60
64 #endif /* !defined SECSPERMIN */
65 
66 #ifndef MINSPERHOUR
67 #define MINSPERHOUR	60
68 #endif /* !defined MINSPERHOUR */
69 
70 #ifndef SECSPERHOUR
71 #define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
72 #endif /* !defined SECSPERHOUR */
73 
74 #ifndef HOURSPERDAY
75 #define HOURSPERDAY	24
76 #endif /* !defined HOURSPERDAY */
77 
78 #ifndef EPOCH_YEAR
79 #define EPOCH_YEAR	1970
80 #endif /* !defined EPOCH_YEAR */
81 
82 #ifndef TM_YEAR_BASE
83 #define TM_YEAR_BASE	1900
84 #endif /* !defined TM_YEAR_BASE */
85 
86 #ifndef DAYSPERNYEAR
87 #define DAYSPERNYEAR	365
88 #endif /* !defined DAYSPERNYEAR */
89 
90 #ifndef isleap
91 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
92 #endif /* !defined isleap */
93 
94 #ifndef isleap_sum
95 /*
96 ** See tzfile.h for details on isleap_sum.
97 */
98 #define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
99 #endif /* !defined isleap_sum */
100 
101 #define SECSPERDAY	((long) SECSPERHOUR * HOURSPERDAY)
102 #define SECSPERNYEAR	(SECSPERDAY * DAYSPERNYEAR)
103 #define SECSPERLYEAR	(SECSPERNYEAR + SECSPERDAY)
104 
105 #ifndef HAVE_GETTEXT
106 #define HAVE_GETTEXT 0
107 #endif
108 #if HAVE_GETTEXT
109 #include "locale.h"	/* for setlocale */
110 #include "libintl.h"
111 #endif /* HAVE_GETTEXT */
112 
113 #ifndef GNUC_or_lint
114 #ifdef lint
115 #define GNUC_or_lint
116 #else /* !defined lint */
117 #ifdef __GNUC__
118 #define GNUC_or_lint
119 #endif /* defined __GNUC__ */
120 #endif /* !defined lint */
121 #endif /* !defined GNUC_or_lint */
122 
123 #ifndef INITIALIZE
124 #ifdef GNUC_or_lint
125 #define INITIALIZE(x)	((x) = 0)
126 #else /* !defined GNUC_or_lint */
127 #define INITIALIZE(x)
128 #endif /* !defined GNUC_or_lint */
129 #endif /* !defined INITIALIZE */
130 
131 /*
132 ** For the benefit of GNU folk...
133 ** `_(MSGID)' uses the current locale's message library string for MSGID.
134 ** The default is to use gettext if available, and use MSGID otherwise.
135 */
136 
137 #ifndef _
138 #if HAVE_GETTEXT
139 #define _(msgid) gettext(msgid)
140 #else /* !HAVE_GETTEXT */
141 #define _(msgid) __UNCONST(msgid)
142 #endif /* !HAVE_GETTEXT */
143 #endif /* !defined _ */
144 
145 #ifndef TZ_DOMAIN
146 #define TZ_DOMAIN "tz"
147 #endif /* !defined TZ_DOMAIN */
148 
149 extern char **	environ;
150 extern int	getopt(int argc, char * const argv[],
151 			const char * options);
152 extern char *	optarg;
153 extern int	optind;
154 
155 static time_t	absolute_min_time;
156 static time_t	absolute_max_time;
157 static size_t	longest;
158 static char *	progname;
159 static int	warned;
160 
161 static const char *	abbr(struct tm * tmp);
162 static void	abbrok(const char * abbrp, const char * zone);
163 static long	delta(struct tm * newp, struct tm * oldp);
164 static void	dumptime(const struct tm * tmp);
165 static time_t	hunt(char * name, time_t lot, time_t	hit);
166 int		main(int, char **);
167 static void	setabsolutes(void);
168 static void	show(char * zone, time_t t, int v);
169 static const char *	tformat(void);
170 static time_t	yeartot(long y);
171 
172 #ifndef TYPECHECK
173 #define my_localtime	localtime
174 #else /* !defined TYPECHECK */
175 static struct tm *
176 my_localtime(tp)
177 time_t *	tp;
178 {
179 	register struct tm *	tmp;
180 
181 	tmp = localtime(tp);
182 	if (tp != NULL && tmp != NULL) {
183 		struct tm	tm;
184 		register time_t	t;
185 
186 		tm = *tmp;
187 		t = mktime(&tm);
188 		if (t - *tp >= 1 || *tp - t >= 1) {
189 			(void) fflush(stdout);
190 			(void) fprintf(stderr, "\n%s: ", progname);
191 			(void) fprintf(stderr, tformat(), *tp);
192 			(void) fprintf(stderr, " ->");
193 			(void) fprintf(stderr, " year=%d", tmp->tm_year);
194 			(void) fprintf(stderr, " mon=%d", tmp->tm_mon);
195 			(void) fprintf(stderr, " mday=%d", tmp->tm_mday);
196 			(void) fprintf(stderr, " hour=%d", tmp->tm_hour);
197 			(void) fprintf(stderr, " min=%d", tmp->tm_min);
198 			(void) fprintf(stderr, " sec=%d", tmp->tm_sec);
199 			(void) fprintf(stderr, " isdst=%d", tmp->tm_isdst);
200 			(void) fprintf(stderr, " -> ");
201 			(void) fprintf(stderr, tformat(), t);
202 			(void) fprintf(stderr, "\n");
203 		}
204 	}
205 	return tmp;
206 }
207 #endif /* !defined TYPECHECK */
208 
209 static void
210 abbrok(abbrp, zone)
211 const char * const	abbrp;
212 const char * const	zone;
213 {
214 	register const char *	cp;
215 	register char *		wp;
216 
217 	if (warned)
218 		return;
219 	cp = abbrp;
220 	wp = NULL;
221 	while (isascii((unsigned char) *cp) && isalpha((unsigned char) *cp))
222 		++cp;
223 	if (cp - abbrp == 0)
224 		wp = _("lacks alphabetic at start");
225 	else if (cp - abbrp < 3)
226 		wp = _("has fewer than 3 alphabetics");
227 	else if (cp - abbrp > 6)
228 		wp = _("has more than 6 alphabetics");
229 	if (wp == NULL && (*cp == '+' || *cp == '-')) {
230 		++cp;
231 		if (isascii((unsigned char) *cp) &&
232 			isdigit((unsigned char) *cp))
233 				if (*cp++ == '1' && *cp >= '0' && *cp <= '4')
234 					++cp;
235 		if (*cp != '\0')
236 			wp = _("differs from POSIX standard");
237 	}
238 	if (wp == NULL)
239 		return;
240 	(void) fflush(stdout);
241 	(void) fprintf(stderr,
242 		_("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"),
243 		progname, zone, abbrp, wp);
244 	warned = TRUE;
245 }
246 
247 static void
248 usage(const char *xprogname, FILE *stream, int status)
249 {
250 	(void) fprintf(stream,
251 _("%s: usage is %s [ --version ] [ --help ] [ -v ] [ -c [loyear,]hiyear ] zonename ...\n\
252 \n\
253 Report bugs to tz@elsie.nci.nih.gov.\n"),
254 		       xprogname, xprogname);
255 	exit(status);
256 }
257 
258 int
259 main(argc, argv)
260 int	argc;
261 char *	argv[];
262 {
263 	register int		i;
264 	register int		c;
265 	register int		vflag;
266 	register char *		cutarg;
267 	register long		cutloyear = ZDUMP_LO_YEAR;
268 	register long		cuthiyear = ZDUMP_HI_YEAR;
269 	register time_t		cutlotime;
270 	register time_t		cuthitime;
271 	register char **	fakeenv;
272 	time_t			now;
273 	time_t			t;
274 	time_t			newt;
275 	struct tm		tm;
276 	struct tm		newtm;
277 	register struct tm *	tmp;
278 	register struct tm *	newtmp;
279 
280 	INITIALIZE(cutlotime);
281 	INITIALIZE(cuthitime);
282 #if HAVE_GETTEXT
283 	(void) setlocale(LC_ALL, "");
284 #ifdef TZ_DOMAINDIR
285 	(void) bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
286 #endif /* defined TEXTDOMAINDIR */
287 	(void) textdomain(TZ_DOMAIN);
288 #endif /* HAVE_GETTEXT */
289 	progname = argv[0];
290 	for (i = 1; i < argc; ++i)
291 		if (strcmp(argv[i], "--version") == 0) {
292 			(void) printf("%s\n", elsieid);
293 			exit(EXIT_SUCCESS);
294 		} else if (strcmp(argv[i], "--help") == 0) {
295 			usage(progname, stdout, EXIT_SUCCESS);
296 		}
297 	vflag = 0;
298 	cutarg = NULL;
299 	while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
300 		if (c == 'v')
301 			vflag = 1;
302 		else	cutarg = optarg;
303 	if ((c != EOF && c != -1) ||
304 		(optind == argc - 1 && strcmp(argv[optind], "=") == 0)) {
305 			usage(progname, stderr, EXIT_FAILURE);
306 	}
307 	if (vflag) {
308 		if (cutarg != NULL) {
309 			long	lo;
310 			long	hi;
311 			char	dummy;
312 
313 			if (sscanf(cutarg, "%ld%c", &hi, &dummy) == 1) {
314 				cuthiyear = hi;
315 			} else if (sscanf(cutarg, "%ld,%ld%c",
316 				&lo, &hi, &dummy) == 2) {
317 					cutloyear = lo;
318 					cuthiyear = hi;
319 			} else {
320 (void) fprintf(stderr, _("%s: wild -c argument %s\n"),
321 					progname, cutarg);
322 				exit(EXIT_FAILURE);
323 			}
324 		}
325 		setabsolutes();
326 		cutlotime = yeartot(cutloyear);
327 		cuthitime = yeartot(cuthiyear);
328 	}
329 	(void) time(&now);
330 	longest = 0;
331 	for (i = optind; i < argc; ++i)
332 		if (strlen(argv[i]) > longest)
333 			longest = strlen(argv[i]);
334 	{
335 		register int	from;
336 		register int	to;
337 
338 		for (i = 0; environ[i] != NULL; ++i)
339 			continue;
340 		fakeenv = (char **) malloc((size_t) ((i + 2) *
341 			sizeof *fakeenv));
342 		if (fakeenv == NULL ||
343 			(fakeenv[0] = (char *) malloc(longest + 4)) == NULL) {
344 			err(EXIT_FAILURE, "Can't allocated %zu bytes",
345 			    longest + 4);
346 		}
347 		to = 0;
348 		(void)strcpy(fakeenv[to++], "TZ=");	/* XXX strcpy is safe */
349 		for (from = 0; environ[from] != NULL; ++from)
350 			if (strncmp(environ[from], "TZ=", 3) != 0)
351 				fakeenv[to++] = environ[from];
352 		fakeenv[to] = NULL;
353 		environ = fakeenv;
354 	}
355 	for (i = optind; i < argc; ++i) {
356 		static char	buf[MAX_STRING_LENGTH];
357 
358 		(void) strcpy(&fakeenv[0][3], argv[i]);	/* XXX strcpy is safe */
359 		if (!vflag) {
360 			show(argv[i], now, FALSE);
361 			continue;
362 		}
363 		warned = FALSE;
364 		t = absolute_min_time;
365 		show(argv[i], t, TRUE);
366 		t += SECSPERHOUR * HOURSPERDAY;
367 		show(argv[i], t, TRUE);
368 		if (t < cutlotime)
369 			t = cutlotime;
370 		tmp = my_localtime(&t);
371 		if (tmp != NULL) {
372 			tm = *tmp;
373 			(void) strncpy(buf, abbr(&tm), (sizeof buf) - 1);
374 		}
375 		for ( ; ; ) {
376 			if (t >= cuthitime || t >= cuthitime - SECSPERHOUR * 12)
377 				break;
378 			newt = t + SECSPERHOUR * 12;
379 			newtmp = localtime(&newt);
380 			if (newtmp != NULL)
381 				newtm = *newtmp;
382 			if ((tmp == NULL || newtmp == NULL) ? (tmp != newtmp) :
383 				(delta(&newtm, &tm) != (newt - t) ||
384 				newtm.tm_isdst != tm.tm_isdst ||
385 				strcmp(abbr(&newtm), buf) != 0)) {
386 					newt = hunt(argv[i], t, newt);
387 					newtmp = localtime(&newt);
388 					if (newtmp != NULL) {
389 						newtm = *newtmp;
390 						(void) strncpy(buf,
391 							abbr(&newtm),
392 							(sizeof buf) - 1);
393 					}
394 			}
395 			t = newt;
396 			tm = newtm;
397 			tmp = newtmp;
398 		}
399 		t = absolute_max_time;
400 		t -= SECSPERHOUR * HOURSPERDAY;
401 		show(argv[i], t, TRUE);
402 		t += SECSPERHOUR * HOURSPERDAY;
403 		show(argv[i], t, TRUE);
404 	}
405 	if (fflush(stdout) || ferror(stdout)) {
406 		err(EXIT_FAILURE, _("Error writing standard output"));
407 	}
408 	exit(EXIT_SUCCESS);
409 	/* If exit fails to exit... */
410 	return EXIT_FAILURE;
411 }
412 
413 static void
414 setabsolutes(void)
415 {
416 	if (0.5 == (time_t) 0.5) {
417 		/*
418 		** time_t is floating.
419 		*/
420 		if (sizeof (time_t) == sizeof (float)) {
421 			absolute_min_time = (time_t) -FLT_MAX;
422 			absolute_max_time = (time_t) FLT_MAX;
423 		} else if (sizeof (time_t) == sizeof (double)) {
424 			absolute_min_time = (time_t) -DBL_MAX;
425 			absolute_max_time = (time_t) DBL_MAX;
426 		} else {
427 			(void) fprintf(stderr,
428 _("%s: use of -v on system with floating time_t other than float or double\n"),
429 				progname);
430 			exit(EXIT_FAILURE);
431 		}
432 	} else if (0 > (time_t) -1) {
433 		/*
434 		** time_t is signed.  Assume overflow wraps around.
435 		*/
436 		time_t t = 0;
437 		time_t t1 = 1;
438 
439 		while (t < t1) {
440 			t = t1;
441 			t1 = 2 * t1 + 1;
442 		}
443 
444 		absolute_max_time = t;
445 		t = -t;
446 		absolute_min_time = t - 1;
447 		if (t < absolute_min_time)
448 			absolute_min_time = t;
449 	} else {
450 		/*
451 		** time_t is unsigned.
452 		*/
453 		absolute_min_time = 0;
454 		absolute_max_time = absolute_min_time - 1;
455 	}
456 }
457 
458 static time_t
459 yeartot(y)
460 const long	y;
461 {
462 	register long	myy;
463 	register long	seconds;
464 	register time_t	t;
465 
466 	myy = EPOCH_YEAR;
467 	t = 0;
468 	while (myy != y) {
469 		if (myy < y) {
470 			seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
471 			++myy;
472 			if (t > absolute_max_time - seconds) {
473 				t = absolute_max_time;
474 				break;
475 			}
476 			t += seconds;
477 		} else {
478 			--myy;
479 			seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
480 			if (t < absolute_min_time + seconds) {
481 				t = absolute_min_time;
482 				break;
483 			}
484 			t -= seconds;
485 		}
486 	}
487 	return t;
488 }
489 
490 static time_t
491 hunt(char *name, time_t lot, time_t hit)
492 {
493 	time_t			t;
494 	long			diff;
495 	struct tm		lotm;
496 	register struct tm *	lotmp;
497 	struct tm		tm;
498 	register struct tm *	tmp;
499 	char			loab[MAX_STRING_LENGTH];
500 
501 	lotmp = my_localtime(&lot);
502 	if (lotmp != NULL) {
503 		lotm = *lotmp;
504 		(void) strncpy(loab, abbr(&lotm), (sizeof loab) - 1);
505 	}
506 	for ( ; ; ) {
507 		diff = (long) (hit - lot);
508 		if (diff < 2)
509 			break;
510 		t = lot;
511 		t += diff / 2;
512 		if (t <= lot)
513 			++t;
514 		else if (t >= hit)
515 			--t;
516 		tmp = my_localtime(&t);
517 		if (tmp != NULL)
518 			tm = *tmp;
519 		if ((lotmp == NULL || tmp == NULL) ? (lotmp == tmp) :
520 			(delta(&tm, &lotm) == (t - lot) &&
521 			tm.tm_isdst == lotm.tm_isdst &&
522 			strcmp(abbr(&tm), loab) == 0)) {
523 				lot = t;
524 				lotm = tm;
525 				lotmp = tmp;
526 		} else	hit = t;
527 	}
528 	show(name, lot, TRUE);
529 	show(name, hit, TRUE);
530 	return hit;
531 }
532 
533 /*
534 ** Thanks to Paul Eggert for logic used in delta.
535 */
536 
537 static long
538 delta(newp, oldp)
539 struct tm *	newp;
540 struct tm *	oldp;
541 {
542 	register long	result;
543 	register int	tmy;
544 
545 	if (newp->tm_year < oldp->tm_year)
546 		return -delta(oldp, newp);
547 	result = 0;
548 	for (tmy = oldp->tm_year; tmy < newp->tm_year; ++tmy)
549 		result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
550 	result += newp->tm_yday - oldp->tm_yday;
551 	result *= HOURSPERDAY;
552 	result += newp->tm_hour - oldp->tm_hour;
553 	result *= MINSPERHOUR;
554 	result += newp->tm_min - oldp->tm_min;
555 	result *= SECSPERMIN;
556 	result += newp->tm_sec - oldp->tm_sec;
557 	return result;
558 }
559 
560 static void
561 show(char *zone, time_t t, int v)
562 {
563 	register struct tm *	tmp;
564 
565 	(void) printf("%-*s  ", (int) longest, zone);
566 	if (v) {
567 		tmp = gmtime(&t);
568 		if (tmp == NULL) {
569 			(void) printf(tformat(), t);
570 		} else {
571 			dumptime(tmp);
572 			(void) printf(" UTC");
573 		}
574 		(void) printf(" = ");
575 	}
576 	tmp = my_localtime(&t);
577 	dumptime(tmp);
578 	if (tmp != NULL) {
579 		if (*abbr(tmp) != '\0')
580 			(void) printf(" %s", abbr(tmp));
581 		if (v) {
582 			(void) printf(" isdst=%d", tmp->tm_isdst);
583 #ifdef TM_GMTOFF
584 			(void) printf(" gmtoff=%ld", tmp->TM_GMTOFF);
585 #endif /* defined TM_GMTOFF */
586 		}
587 	}
588 	(void) printf("\n");
589 	if (tmp != NULL && *abbr(tmp) != '\0')
590 		abbrok(abbr(tmp), zone);
591 }
592 
593 static const char *
594 abbr(tmp)
595 struct tm *	tmp;
596 {
597 	register const char *	result;
598 	static const char	nada;
599 
600 	if (tmp->tm_isdst != 0 && tmp->tm_isdst != 1)
601 		return &nada;
602 	result = tzname[tmp->tm_isdst];
603 	return (result == NULL) ? &nada : result;
604 }
605 
606 /*
607 ** The code below can fail on certain theoretical systems;
608 ** it works on all known real-world systems as of 2004-12-30.
609 */
610 
611 static const char *
612 tformat(void)
613 {
614 	if (0.5 == (time_t) 0.5) {	/* floating */
615 		if (sizeof (time_t) > sizeof (double))
616 			return "%Lg";
617 		return "%g";
618 	}
619 	if (0 > (time_t) -1) {		/* signed */
620 		if (sizeof (time_t) > sizeof (long))
621 			return "%lld";
622 		if (sizeof (time_t) > sizeof (int))
623 			return "%ld";
624 		return "%d";
625 	}
626 	if (sizeof (time_t) > sizeof (unsigned long))
627 		return "%llu";
628 	if (sizeof (time_t) > sizeof (unsigned int))
629 		return "%lu";
630 	return "%u";
631 }
632 
633 static void
634 dumptime(timeptr)
635 register const struct tm *	timeptr;
636 {
637 	static const char	wday_name[][3] = {
638 		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
639 	};
640 	static const char	mon_name[][3] = {
641 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
642 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
643 	};
644 	register const char *	wn;
645 	register const char *	mn;
646 	register int		lead;
647 	register int		trail;
648 
649 	if (timeptr == NULL) {
650 		(void) printf("NULL");
651 		return;
652 	}
653 	/*
654 	** The packaged versions of localtime and gmtime never put out-of-range
655 	** values in tm_wday or tm_mon, but since this code might be compiled
656 	** with other (perhaps experimental) versions, paranoia is in order.
657 	*/
658 	if (timeptr->tm_wday < 0 || timeptr->tm_wday >=
659 		(int) (sizeof wday_name / sizeof wday_name[0]))
660 			wn = "???";
661 	else		wn = wday_name[timeptr->tm_wday];
662 	if (timeptr->tm_mon < 0 || timeptr->tm_mon >=
663 		(int) (sizeof mon_name / sizeof mon_name[0]))
664 			mn = "???";
665 	else		mn = mon_name[timeptr->tm_mon];
666 	(void) printf("%.3s %.3s%3d %.2d:%.2d:%.2d ",
667 		wn, mn,
668 		timeptr->tm_mday, timeptr->tm_hour,
669 		timeptr->tm_min, timeptr->tm_sec);
670 #define DIVISOR	10
671 	trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
672 	lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
673 		trail / DIVISOR;
674 	trail %= DIVISOR;
675 	if (trail < 0 && lead > 0) {
676 		trail += DIVISOR;
677 		--lead;
678 	} else if (lead < 0 && trail > 0) {
679 		trail -= DIVISOR;
680 		++lead;
681 	}
682 	if (lead == 0)
683 		(void) printf("%d", trail);
684 	else	(void) printf("%d%d", lead, ((trail < 0) ? -trail : trail));
685 }
686