text: /*
  ** This file is in the public domain, so clarified as of
  ** 1996-06-05 by Arthur David Olson.
  */
  
  #ifndef lint
  #ifndef NOID
  static char	elsieid[] = "@(#)localtime.c	8.9";
  #endif /* !defined NOID */
  #endif /* !defined lint */
  
  /*
  ** Leap second handling from Bradley White.
  ** POSIX-style TZ environment variable handling from Guy Harris.
  */
  
  /*LINTLIBRARY*/
  
  #include "private.h"
  #include "tzfile.h"
  #include "fcntl.h"
  #include "float.h"	/* for FLT_MAX and DBL_MAX */
  
  #ifndef TZ_ABBR_MAX_LEN
  #define TZ_ABBR_MAX_LEN	16
  #endif /* !defined TZ_ABBR_MAX_LEN */
  
  #ifndef TZ_ABBR_CHAR_SET
  #define TZ_ABBR_CHAR_SET \
  	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
  #endif /* !defined TZ_ABBR_CHAR_SET */
  
  #ifndef TZ_ABBR_ERR_CHAR
  #define TZ_ABBR_ERR_CHAR	'_'
  #endif /* !defined TZ_ABBR_ERR_CHAR */
  
  /*
  ** SunOS 4.1.1 headers lack O_BINARY.
  */
  
  #ifdef O_BINARY
  #define OPEN_MODE	(O_RDONLY | O_BINARY)
  #endif /* defined O_BINARY */
  #ifndef O_BINARY
  #define OPEN_MODE	O_RDONLY
  #endif /* !defined O_BINARY */
  
  #ifndef WILDABBR
  /*
  ** Someone might make incorrect use of a time zone abbreviation:
  **	1.	They might reference tzname[0] before calling tzset (explicitly
  **		or implicitly).
  **	2.	They might reference tzname[1] before calling tzset (explicitly
  **		or implicitly).
  **	3.	They might reference tzname[1] after setting to a time zone
  **		in which Daylight Saving Time is never observed.
  **	4.	They might reference tzname[0] after setting to a time zone
  **		in which Standard Time is never observed.
  **	5.	They might reference tm.TM_ZONE after calling offtime.
  ** What's best to do in the above cases is open to debate;
  ** for now, we just set things up so that in any of the five cases
  ** WILDABBR is used. Another possibility: initialize tzname[0] to the
  ** string "tzname[0] used before set", and similarly for the other cases.
  ** And another: initialize tzname[0] to "ERA", with an explanation in the
  ** manual page of what this "time zone abbreviation" means (doing this so
  ** that tzname[0] has the "normal" length of three characters).
  */
  #define WILDABBR	"   "
  #endif /* !defined WILDABBR */
  
  static char		wildabbr[] = WILDABBR;
  
  static const char	gmt[] = "GMT";
  
  /*
  ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
  ** We default to US rules as of 1999-08-17.
  ** POSIX 1003.1 section 8.1.1 says that the default DST rules are
  ** implementation dependent; for historical reasons, US rules are a
  ** common default.
  */
  #ifndef TZDEFRULESTRING
  #define TZDEFRULESTRING ",M4.1.0,M10.5.0"
  #endif /* !defined TZDEFDST */
  
  struct ttinfo {				/* time type information */
  	long		tt_gmtoff;	/* UTC offset in seconds */
  	int		tt_isdst;	/* used to set tm_isdst */
  	int		tt_abbrind;	/* abbreviation list index */
  	int		tt_ttisstd;	/* TRUE if transition is std time */
  	int		tt_ttisgmt;	/* TRUE if transition is UTC */
  };
  
  struct lsinfo {				/* leap second information */
  	time_t		ls_trans;	/* transition time */
  	long		ls_corr;	/* correction to apply */
  };
  
  #define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))
  
  #ifdef TZNAME_MAX
  #define MY_TZNAME_MAX	TZNAME_MAX
  #endif /* defined TZNAME_MAX */
  #ifndef TZNAME_MAX
  #define MY_TZNAME_MAX	255
  #endif /* !defined TZNAME_MAX */
  
  struct state {
  	int		leapcnt;
  	int		timecnt;
  	int		typecnt;
  	int		charcnt;
  	int		goback;
  	int		goahead;
  	time_t		ats[TZ_MAX_TIMES];
  	unsigned char	types[TZ_MAX_TIMES];
  	struct ttinfo	ttis[TZ_MAX_TYPES];
  	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
  				(2 * (MY_TZNAME_MAX + 1)))];
  	struct lsinfo	lsis[TZ_MAX_LEAPS];
  };
  
  struct rule {
  	int		r_type;		/* type of rule--see below */
  	int		r_day;		/* day number of rule */
  	int		r_week;		/* week number of rule */
  	int		r_mon;		/* month number of rule */
  	long		r_time;		/* transition time of rule */
  };
  
  #define JULIAN_DAY		0	/* Jn - Julian day */
  #define DAY_OF_YEAR		1	/* n - day of year */
  #define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */
  
  /*
  ** Prototypes for static functions.
  */
  
  static long		detzcode(const char * codep);
  static time_t		detzcode64(const char * codep);
  static int		differ_by_repeat(time_t t1, time_t t0);
  static const char *	getzname(const char * strp);
  static const char *	getqzname(const char * strp, const int delim);
  static const char *	getnum(const char * strp, int * nump, int min,
  				int max);
  static const char *	getsecs(const char * strp, long * secsp);
  static const char *	getoffset(const char * strp, long * offsetp);
  static const char *	getrule(const char * strp, struct rule * rulep);
  static void		gmtload(struct state * sp);
  static struct tm *	gmtsub(const time_t * timep, long offset,
  				struct tm * tmp);
  static struct tm *	localsub(const time_t * timep, long offset,
  				struct tm * tmp);
  static int		increment_overflow(int * number, int delta);
  static int		leaps_thru_end_of(int y);
  static int		long_increment_overflow(long * number, int delta);
  static int		long_normalize_overflow(long * tensptr,
  				int * unitsptr, int base);
  static int		normalize_overflow(int * tensptr, int * unitsptr,
  				int base);
  static void		settzname(void);
  static time_t		time1(struct tm * tmp,
  				struct tm * (*funcp)(const time_t *,
  				long, struct tm *),
  				long offset);
  static time_t		time2(struct tm *tmp,
  				struct tm * (*funcp)(const time_t *,
  				long, struct tm*),
  				long offset, int * okayp);
  static time_t		time2sub(struct tm *tmp,
  				struct tm * (*funcp)(const time_t *,
  				long, struct tm*),
  				long offset, int * okayp, int do_norm_secs);
  static struct tm *	timesub(const time_t * timep, long offset,
  				const struct state * sp, struct tm * tmp);
  static int		tmcomp(const struct tm * atmp,
  				const struct tm * btmp);
  static time_t		transtime(time_t janfirst, int year,
  				const struct rule * rulep, long offset);
  static int		typesequiv(const struct state * sp, int a, int b);
  static int		tzload(const char * name, struct state * sp,
  				int doextend);
  static int		tzparse(const char * name, struct state * sp,
  				int lastditch);
  
  #ifdef ALL_STATE
  static struct state *	lclptr;
  static struct state *	gmtptr;
  #endif /* defined ALL_STATE */
  
  #ifndef ALL_STATE
  static struct state	lclmem;
  static struct state	gmtmem;
  #define lclptr		(&lclmem)
  #define gmtptr		(&gmtmem)
  #endif /* State Farm */
  
  #ifndef TZ_STRLEN_MAX
  #define TZ_STRLEN_MAX 255
  #endif /* !defined TZ_STRLEN_MAX */
  
  static char		lcl_TZname[TZ_STRLEN_MAX + 1];
  static int		lcl_is_set;
  static int		gmt_is_set;
  
  char *			tzname[2] = {
  	wildabbr,
  	wildabbr
  };
  
  /*
  ** Section 4.12.3 of X3.159-1989 requires that
  **	Except for the strftime function, these functions [asctime,
  **	ctime, gmtime, localtime] return values in one of two static
  **	objects: a broken-down time structure and an array of char.
  ** Thanks to Paul Eggert for noting this.
  */
  
  static struct tm	tm;
  
  #ifdef USG_COMPAT
  time_t			timezone = 0;
  int			daylight = 0;
  #endif /* defined USG_COMPAT */
  
  #ifdef ALTZONE
  time_t			altzone = 0;
  #endif /* defined ALTZONE */
  
  static long
  detzcode(codep)
  const char * const	codep;
  {
  	register long	result;
  	register int	i;
  
  	result = (codep[0] & 0x80) ? ~0L : 0;
  	for (i = 0; i < 4; ++i)
  		result = (result << 8) | (codep[i] & 0xff);
  	return result;
  }
  
  static time_t
  detzcode64(codep)
  const char * const	codep;
  {
  	register time_t	result;
  	register int	i;
  
  	result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
  	for (i = 0; i < 8; ++i)
  		result = result * 256 + (codep[i] & 0xff);
  	return result;
  }
  
  static void
  settzname(void)
  {
  	register struct state * const	sp = lclptr;
  	register int			i;
  
  	tzname[0] = wildabbr;
  	tzname[1] = wildabbr;
  #ifdef USG_COMPAT
  	daylight = 0;
  	timezone = 0;
  #endif /* defined USG_COMPAT */
  #ifdef ALTZONE
  	altzone = 0;
  #endif /* defined ALTZONE */
  #ifdef ALL_STATE
  	if (sp == NULL) {
  		tzname[0] = tzname[1] = gmt;
  		return;
  	}
  #endif /* defined ALL_STATE */
  	for (i = 0; i < sp->typecnt; ++i) {
  		register const struct ttinfo * const	ttisp = &sp->ttis[i];
  
  		tzname[ttisp->tt_isdst] =
  			&sp->chars[ttisp->tt_abbrind];
  #ifdef USG_COMPAT
  		if (ttisp->tt_isdst)
  			daylight = 1;
  		if (i == 0 || !ttisp->tt_isdst)
  			timezone = -(ttisp->tt_gmtoff);
  #endif /* defined USG_COMPAT */
  #ifdef ALTZONE
  		if (i == 0 || ttisp->tt_isdst)
  			altzone = -(ttisp->tt_gmtoff);
  #endif /* defined ALTZONE */
  	}
  	/*
  	** And to get the latest zone names into tzname. . .
  	*/
  	for (i = 0; i < sp->timecnt; ++i) {
  		register const struct ttinfo * const	ttisp =
  							&sp->ttis[
  								sp->types[i]];
  
  		tzname[ttisp->tt_isdst] =
  			&sp->chars[ttisp->tt_abbrind];
  	}
  	/*
  	** Finally, scrub the abbreviations.
  	** First, replace bogus characters.
  	*/
  	for (i = 0; i < sp->charcnt; ++i)
  		if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
  			sp->chars[i] = TZ_ABBR_ERR_CHAR;
  	/*
  	** Second, truncate long abbreviations.
  	*/
  	for (i = 0; i < sp->typecnt; ++i) {
  		register const struct ttinfo * const	ttisp = &sp->ttis[i];
  		register char *				cp = &sp->chars[ttisp->tt_abbrind];
  
  		if (strlen(cp) > TZ_ABBR_MAX_LEN &&
  			strcmp(cp, GRANDPARENTED) != 0)
  				*(cp + TZ_ABBR_MAX_LEN) = '\0';
  	}
  }
  
  static int
  differ_by_repeat(t1, t0)
  const time_t	t1;
  const time_t	t0;
  {
  	if (TYPE_INTEGRAL(time_t) &&
  		TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
  			return 0;
  	return t1 - t0 == SECSPERREPEAT;
  }
  
  static int
  tzload(name, sp, doextend)
  register const char *		name;
  register struct state * const	sp;
  register const int		doextend;
  {
  	register const char *		p;
  	register int			i;
  	register int			fid;
  	register int			stored;
  	register int			nread;
  	union {
  		struct tzhead	tzhead;
  		char		buf[2 * sizeof(struct tzhead) +
  					2 * sizeof *sp +
  					4 * TZ_MAX_TIMES];
  	} u;
  
  	if (name == NULL && (name = TZDEFAULT) == NULL)
  		return -1;
  	{
  		register int	doaccess;
  		/*
  		** Section 4.9.1 of the C standard says that
  		** "FILENAME_MAX expands to an integral constant expression
  		** that is the size needed for an array of char large enough
  		** to hold the longest file name string that the implementation
  		** guarantees can be opened."
  		*/
  		char		fullname[FILENAME_MAX + 1];
  
  		if (name[0] == ':')
  			++name;
  		doaccess = name[0] == '/';
  		if (!doaccess) {
  			if ((p = TZDIR) == NULL)
  				return -1;
  			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
  				return -1;
  			(void) strcpy(fullname, p);
  			(void) strcat(fullname, "/");
  			(void) strcat(fullname, name);
  			/*
  			** Set doaccess if '.' (as in "../") shows up in name.
  			*/
  			if (strchr(name, '.') != NULL)
  				doaccess = TRUE;
  			name = fullname;
  		}
  		if (doaccess && access(name, R_OK) != 0)
  			return -1;
  		if ((fid = open(name, OPEN_MODE)) == -1)
  			return -1;
  	}
  	nread = read(fid, u.buf, sizeof u.buf);
  	if (close(fid) < 0 || nread <= 0)
  		return -1;
  	for (stored = 4; stored <= 8; stored *= 2) {
  		int		ttisstdcnt;
  		int		ttisgmtcnt;
  
  		ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
  		ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
  		sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
  		sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
  		sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
  		sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
  		p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
  		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
  			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
  			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
  			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
  			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
  			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
  				return -1;
  		if (nread - (p - u.buf) <
  			sp->timecnt * stored +		/* ats */
  			sp->timecnt +			/* types */
  			sp->typecnt * 6 +		/* ttinfos */
  			sp->charcnt +			/* chars */
  			sp->leapcnt * (stored + 4) +	/* lsinfos */
  			ttisstdcnt +			/* ttisstds */
  			ttisgmtcnt)			/* ttisgmts */
  				return -1;
  		for (i = 0; i < sp->timecnt; ++i) {
  			sp->ats[i] = (stored == 4) ?
  				detzcode(p) : detzcode64(p);
  			p += stored;
  		}
  		for (i = 0; i < sp->timecnt; ++i) {
  			sp->types[i] = (unsigned char) *p++;
  			if (sp->types[i] >= sp->typecnt)
  				return -1;
  		}
  		for (i = 0; i < sp->typecnt; ++i) {
  			register struct ttinfo *	ttisp;
  
  			ttisp = &sp->ttis[i];
  			ttisp->tt_gmtoff = detzcode(p);
  			p += 4;
  			ttisp->tt_isdst = (unsigned char) *p++;
  			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
  				return -1;
  			ttisp->tt_abbrind = (unsigned char) *p++;
  			if (ttisp->tt_abbrind < 0 ||
  				ttisp->tt_abbrind > sp->charcnt)
  					return -1;
  		}
  		for (i = 0; i < sp->charcnt; ++i)
  			sp->chars[i] = *p++;
  		sp->chars[i] = '\0';	/* ensure '\0' at end */
  		for (i = 0; i < sp->leapcnt; ++i) {
  			register struct lsinfo *	lsisp;
  
  			lsisp = &sp->lsis[i];
  			lsisp->ls_trans = (stored == 4) ?
  				detzcode(p) : detzcode64(p);
  			p += stored;
  			lsisp->ls_corr = detzcode(p);
  			p += 4;
  		}
  		for (i = 0; i < sp->typecnt; ++i) {
  			register struct ttinfo *	ttisp;
  
  			ttisp = &sp->ttis[i];
  			if (ttisstdcnt == 0)
  				ttisp->tt_ttisstd = FALSE;
  			else {
  				ttisp->tt_ttisstd = *p++;
  				if (ttisp->tt_ttisstd != TRUE &&
  					ttisp->tt_ttisstd != FALSE)
  						return -1;
  			}
  		}
  		for (i = 0; i < sp->typecnt; ++i) {
  			register struct ttinfo *	ttisp;
  
  			ttisp = &sp->ttis[i];
  			if (ttisgmtcnt == 0)
  				ttisp->tt_ttisgmt = FALSE;
  			else {
  				ttisp->tt_ttisgmt = *p++;
  				if (ttisp->tt_ttisgmt != TRUE &&
  					ttisp->tt_ttisgmt != FALSE)
  						return -1;
  			}
  		}
  		/*
  		** Out-of-sort ats should mean we're running on a
  		** signed time_t system but using a data file with
  		** unsigned values (or vice versa).
  		*/
  		for (i = 0; i < sp->timecnt - 2; ++i)
  			if (sp->ats[i] > sp->ats[i + 1]) {
  				++i;
  				if (TYPE_SIGNED(time_t)) {
  					/*
  					** Ignore the end (easy).
  					*/
  					sp->timecnt = i;
  				} else {
  					/*
  					** Ignore the beginning (harder).
  					*/
  					register int	j;
  
  					for (j = 0; j + i < sp->timecnt; ++j) {
  						sp->ats[j] = sp->ats[j + i];
  						sp->types[j] = sp->types[j + i];
  					}
  					sp->timecnt = j;
  				}
  				break;
  			}
  		/*
  		** If this is an old file, we're done.
  		*/
  		if (u.tzhead.tzh_version[0] == '\0')
  			break;
  		nread -= p - u.buf;
  		for (i = 0; i < nread; ++i)
  			u.buf[i] = p[i];
  		/*
  		** If this is a narrow integer time_t system, we're done.
  		*/
  		if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
  			break;
  	}
  	if (doextend && nread > 2 &&
  		u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
  		sp->typecnt + 2 <= TZ_MAX_TYPES) {
  			struct state	ts;
  			register int	result;
  
  			u.buf[nread - 1] = '\0';
  			result = tzparse(&u.buf[1], &ts, FALSE);
  			if (result == 0 && ts.typecnt == 2 &&
  				sp->charcnt + ts.charcnt <= TZ_MAX_CHARS) {
  					for (i = 0; i < 2; ++i)
  						ts.ttis[i].tt_abbrind +=
  							sp->charcnt;
  					for (i = 0; i < ts.charcnt; ++i)
  						sp->chars[sp->charcnt++] =
  							ts.chars[i];
  					i = 0;
  					while (i < ts.timecnt &&
  						ts.ats[i] <=
  						sp->ats[sp->timecnt - 1])
  							++i;
  					while (i < ts.timecnt &&
  					    sp->timecnt < TZ_MAX_TIMES) {
  						sp->ats[sp->timecnt] =
  							ts.ats[i];
  						sp->types[sp->timecnt] =
  							sp->typecnt +
  							ts.types[i];
  						++sp->timecnt;
  						++i;
  					}
  					sp->ttis[sp->typecnt++] = ts.ttis[0];
  					sp->ttis[sp->typecnt++] = ts.ttis[1];
  			}
  	}
  	sp->goback = sp->goahead = FALSE;
  	if (sp->timecnt > 1) {
  		for (i = 1; i < sp->timecnt; ++i)
  			if (typesequiv(sp, sp->types[i], sp->types[0]) &&
  				differ_by_repeat(sp->ats[i], sp->ats[0])) {
  					sp->goback = TRUE;
  					break;
  				}
  		for (i = sp->timecnt - 2; i >= 0; --i)
  			if (typesequiv(sp, sp->types[sp->timecnt - 1],
  				sp->types[i]) &&
  				differ_by_repeat(sp->ats[sp->timecnt - 1],
  				sp->ats[i])) {
  					sp->goahead = TRUE;
  					break;
  		}
  	}
  	return 0;
  }
  
  static int
  typesequiv(sp, a, b)
  const struct state * const	sp;
  const int			a;
  const int			b;
  {
  	register int	result;
  
  	if (sp == NULL ||
  		a < 0 || a >= sp->typecnt ||
  		b < 0 || b >= sp->typecnt)
  			result = FALSE;
  	else {
  		register const struct ttinfo *	ap = &sp->ttis[a];
  		register const struct ttinfo *	bp = &sp->ttis[b];
  		result = ap->tt_gmtoff == bp->tt_gmtoff &&
  			ap->tt_isdst == bp->tt_isdst &&
  			ap->tt_ttisstd == bp->tt_ttisstd &&
  			ap->tt_ttisgmt == bp->tt_ttisgmt &&
  			strcmp(&sp->chars[ap->tt_abbrind],
  			&sp->chars[bp->tt_abbrind]) == 0;
  	}
  	return result;
  }
  
  static const int	mon_lengths[2][MONSPERYEAR] = {
  	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
  	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
  };
  
  static const int	year_lengths[2] = {
  	DAYSPERNYEAR, DAYSPERLYEAR
  };
  
  /*
  ** Given a pointer into a time zone string, scan until a character that is not
  ** a valid character in a zone name is found. Return a pointer to that
  ** character.
  */
  
  static const char *
  getzname(strp)
  register const char *	strp;
  {
  	register char	c;
  
  	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
  		c != '+')
  			++strp;
  	return strp;
  }
  
  /*
  ** Given a pointer into an extended time zone string, scan until the ending
  ** delimiter of the zone name is located. Return a pointer to the delimiter.
  **
  ** As with getzname above, the legal character set is actually quite
  ** restricted, with other characters producing undefined results.
  ** We don't do any checking here; checking is done later in common-case code.
  */
  
  static const char *
  getqzname(register const char *strp, const int delim)
  {
  	register int	c;
  
  	while ((c = *strp) != '\0' && c != delim)
  		++strp;
  	return strp;
  }
  
  /*
  ** Given a pointer into a time zone string, extract a number from that string.
  ** Check that the number is within a specified range; if it is not, return
  ** NULL.
  ** Otherwise, return a pointer to the first character not part of the number.
  */
  
  static const char *
  getnum(strp, nump, min, max)
  register const char *	strp;
  int * const		nump;
  const int		min;
  const int		max;
  {
  	register char	c;
  	register int	num;
  
  	if (strp == NULL || !is_digit(c = *strp))
  		return NULL;
  	num = 0;
  	do {
  		num = num * 10 + (c - '0');
  		if (num > max)
  			return NULL;	/* illegal value */
  		c = *++strp;
  	} while (is_digit(c));
  	if (num < min)
  		return NULL;		/* illegal value */
  	*nump = num;
  	return strp;
  }
  
  /*
  ** Given a pointer into a time zone string, extract a number of seconds,
  ** in hh[:mm[:ss]] form, from the string.
  ** If any error occurs, return NULL.
  ** Otherwise, return a pointer to the first character not part of the number
  ** of seconds.
  */
  
  static const char *
  getsecs(strp, secsp)
  register const char *	strp;
  long * const		secsp;
  {
  	int	num;
  
  	/*
  	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
  	** "M10.4.6/26", which does not conform to Posix,
  	** but which specifies the equivalent of
  	** ``02:00 on the first Sunday on or after 23 Oct''.
  	*/
  	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
  	if (strp == NULL)
  		return NULL;
  	*secsp = num * (long) SECSPERHOUR;
  	if (*strp == ':') {
  		++strp;
  		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
  		if (strp == NULL)
  			return NULL;
  		*secsp += num * SECSPERMIN;
  		if (*strp == ':') {
  			++strp;
  			/* `SECSPERMIN' allows for leap seconds. */
  			strp = getnum(strp, &num, 0, SECSPERMIN);
  			if (strp == NULL)
  				return NULL;
  			*secsp += num;
  		}
  	}
  	return strp;
  }
  
  /*
  ** Given a pointer into a time zone string, extract an offset, in
  ** [+-]hh[:mm[:ss]] form, from the string.
  ** If any error occurs, return NULL.
  ** Otherwise, return a pointer to the first character not part of the time.
  */
  
  static const char *
  getoffset(strp, offsetp)
  register const char *	strp;
  long * const		offsetp;
  {
  	register int	neg = 0;
  
  	if (*strp == '-') {
  		neg = 1;
  		++strp;
  	} else if (*strp == '+')
  		++strp;
  	strp = getsecs(strp, offsetp);
  	if (strp == NULL)
  		return NULL;		/* illegal time */
  	if (neg)
  		*offsetp = -*offsetp;
  	return strp;
  }
  
  /*
  ** Given a pointer into a time zone string, extract a rule in the form
  ** date[/time]. See POSIX section 8 for the format of "date" and "time".
  ** If a valid rule is not found, return NULL.
  ** Otherwise, return a pointer to the first character not part of the rule.
  */
  
  static const char *
  getrule(strp, rulep)
  const char *			strp;
  register struct rule * const	rulep;
  {
  	if (*strp == 'J') {
  		/*
  		** Julian day.
  		*/
  		rulep->r_type = JULIAN_DAY;
  		++strp;
  		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
  	} else if (*strp == 'M') {
  		/*
  		** Month, week, day.
  		*/
  		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
  		++strp;
  		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
  		if (strp == NULL)
  			return NULL;
  		if (*strp++ != '.')
  			return NULL;
  		strp = getnum(strp, &rulep->r_week, 1, 5);
  		if (strp == NULL)
  			return NULL;
  		if (*strp++ != '.')
  			return NULL;
  		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
  	} else if (is_digit(*strp)) {
  		/*
  		** Day of year.
  		*/
  		rulep->r_type = DAY_OF_YEAR;
  		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
  	} else	return NULL;		/* invalid format */
  	if (strp == NULL)
  		return NULL;
  	if (*strp == '/') {
  		/*
  		** Time specified.
  		*/
  		++strp;
  		strp = getsecs(strp, &rulep->r_time);
  	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
  	return strp;
  }
  
  /*
  ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
  ** year, a rule, and the offset from UTC at the time that rule takes effect,
  ** calculate the Epoch-relative time that rule takes effect.
  */
  
  static time_t
  transtime(janfirst, year, rulep, offset)
  const time_t				janfirst;
  const int				year;
  register const struct rule * const	rulep;
  const long				offset;
  {
  	register int	leapyear;
  	register time_t	value;
  	register int	i;
  	int		d, m1, yy0, yy1, yy2, dow;
  
  	INITIALIZE(value);
  	leapyear = isleap(year);
  	switch (rulep->r_type) {
  
  	case JULIAN_DAY:
  		/*
  		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
  		** years.
  		** In non-leap years, or if the day number is 59 or less, just
  		** add SECSPERDAY times the day number-1 to the time of
  		** January 1, midnight, to get the day.
  		*/
  		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
  		if (leapyear && rulep->r_day >= 60)
  			value += SECSPERDAY;
  		break;
  
  	case DAY_OF_YEAR:
  		/*
  		** n - day of year.
  		** Just add SECSPERDAY times the day number to the time of
  		** January 1, midnight, to get the day.
  		*/
  		value = janfirst + rulep->r_day * SECSPERDAY;
  		break;
  
  	case MONTH_NTH_DAY_OF_WEEK:
  		/*
  		** Mm.n.d - nth "dth day" of month m.
  		*/
  		value = janfirst;
  		for (i = 0; i < rulep->r_mon - 1; ++i)
  			value += mon_lengths[leapyear][i] * SECSPERDAY;
  
  		/*
  		** Use Zeller's Congruence to get day-of-week of first day of
  		** month.
  		*/
  		m1 = (rulep->r_mon + 9) % 12 + 1;
  		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
  		yy1 = yy0 / 100;
  		yy2 = yy0 % 100;
  		dow = ((26 * m1 - 2) / 10 +
  			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
  		if (dow < 0)
  			dow += DAYSPERWEEK;
  
  		/*
  		** "dow" is the day-of-week of the first day of the month. Get
  		** the day-of-month (zero-origin) of the first "dow" day of the
  		** month.
  		*/
  		d = rulep->r_day - dow;
  		if (d < 0)
  			d += DAYSPERWEEK;
  		for (i = 1; i < rulep->r_week; ++i) {
  			if (d + DAYSPERWEEK >=
  				mon_lengths[leapyear][rulep->r_mon - 1])
  					break;
  			d += DAYSPERWEEK;
  		}
  
  		/*
  		** "d" is the day-of-month (zero-origin) of the day we want.
  		*/
  		value += d * SECSPERDAY;
  		break;
  	}
  
  	/*
  	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
  	** question. To get the Epoch-relative time of the specified local
  	** time on that day, add the transition time and the current offset
  	** from UTC.
  	*/
  	return value + rulep->r_time + offset;
  }
  
  /*
  ** Given a POSIX section 8-style TZ string, fill in the rule tables as
  ** appropriate.
  */
  
  static int
  tzparse(name, sp, lastditch)
  const char *			name;
  register struct state * const	sp;
  const int			lastditch;
  {
  	const char *			stdname;
  	const char *			dstname;
  	size_t				stdlen;
  	size_t				dstlen;
  	long				stdoffset;
  	long				dstoffset;
  	register time_t *		atp;
  	register unsigned char *	typep;
  	register char *			cp;
  	register int			load_result;
  
  	INITIALIZE(dstname);
  	stdname = name;
  	if (lastditch) {
  		stdlen = strlen(name);	/* length of standard zone name */
  		name += stdlen;
  		if (stdlen >= sizeof sp->chars)
  			stdlen = (sizeof sp->chars) - 1;
  		stdoffset = 0;
  	} else {
  		if (*name == '<') {
  			name++;
  			stdname = name;
  			name = getqzname(name, '>');
  			if (*name != '>')
  				return (-1);
  			stdlen = name - stdname;
  			name++;
  		} else {
  			name = getzname(name);
  			stdlen = name - stdname;
  		}
  		if (*name == '\0')
  			return -1;
  		name = getoffset(name, &stdoffset);
  		if (name == NULL)
  			return -1;
  	}
  	load_result = tzload(TZDEFRULES, sp, FALSE);
  	if (load_result != 0)
  		sp->leapcnt = 0;		/* so, we're off a little */
  	if (*name != '\0') {
  		if (*name == '<') {
  			dstname = ++name;
  			name = getqzname(name, '>');
  			if (*name != '>')
  				return -1;
  			dstlen = name - dstname;
  			name++;
  		} else {
  			dstname = name;
  			name = getzname(name);
  			dstlen = name - dstname; /* length of DST zone name */
  		}
  		if (*name != '\0' && *name != ',' && *name != ';') {
  			name = getoffset(name, &dstoffset);
  			if (name == NULL)
  				return -1;
  		} else	dstoffset = stdoffset - SECSPERHOUR;
  		if (*name == '\0' && load_result != 0)
  			name = TZDEFRULESTRING;
  		if (*name == ',' || *name == ';') {
  			struct rule	start;
  			struct rule	end;
  			register int	year;
  			register time_t	janfirst;
  			time_t		starttime;
  			time_t		endtime;
  
  			++name;
  			if ((name = getrule(name, &start)) == NULL)
  				return -1;
  			if (*name++ != ',')
  				return -1;
  			if ((name = getrule(name, &end)) == NULL)
  				return -1;
  			if (*name != '\0')
  				return -1;
  			sp->typecnt = 2;	/* standard time and DST */
  			/*
  			** Two transitions per year, from EPOCH_YEAR forward.
  			*/
  			sp->ttis[0].tt_gmtoff = -dstoffset;
  			sp->ttis[0].tt_isdst = 1;
  			sp->ttis[0].tt_abbrind = stdlen + 1;
  			sp->ttis[1].tt_gmtoff = -stdoffset;
  			sp->ttis[1].tt_isdst = 0;
  			sp->ttis[1].tt_abbrind = 0;
  			atp = sp->ats;
  			typep = sp->types;
  			janfirst = 0;
  			sp->timecnt = 0;
  			for (year = EPOCH_YEAR;
  			    sp->timecnt + 2 <= TZ_MAX_TIMES;
  			    ++year) {
  			    	time_t	newfirst;
  
  				starttime = transtime(janfirst, year, &start,
  					stdoffset);
  				endtime = transtime(janfirst, year, &end,
  					dstoffset);
  				if (starttime > endtime) {
  					*atp++ = endtime;
  					*typep++ = 1;	/* DST ends */
  					*atp++ = starttime;
  					*typep++ = 0;	/* DST begins */
  				} else {
  					*atp++ = starttime;
  					*typep++ = 0;	/* DST begins */
  					*atp++ = endtime;
  					*typep++ = 1;	/* DST ends */
  				}
  				sp->timecnt += 2;
  				newfirst = janfirst;
  				newfirst += year_lengths[isleap(year)] *
  					SECSPERDAY;
  				if (newfirst <= janfirst)
  					break;
  				janfirst = newfirst;
  			}
  		} else {
  			register long	theirstdoffset;
  			register long	theirdstoffset;
  			register long	theiroffset;
  			register int	isdst;
  			register int	i;
  			register int	j;
  
  			if (*name != '\0')
  				return -1;
  			/*
  			** Initial values of theirstdoffset and theirdstoffset.
  			*/
  			theirstdoffset = 0;
  			for (i = 0; i < sp->timecnt; ++i) {
  				j = sp->types[i];
  				if (!sp->ttis[j].tt_isdst) {
  					theirstdoffset =
  						-sp->ttis[j].tt_gmtoff;
  					break;
  				}
  			}
  			theirdstoffset = 0;
  			for (i = 0; i < sp->timecnt; ++i) {
  				j = sp->types[i];
  				if (sp->ttis[j].tt_isdst) {
  					theirdstoffset =
  						-sp->ttis[j].tt_gmtoff;
  					break;
  				}
  			}
  			/*
  			** Initially we're assumed to be in standard time.
  			*/
  			isdst = FALSE;
  			theiroffset = theirstdoffset;
  			/*
  			** Now juggle transition times and types
  			** tracking offsets as you do.
  			*/
  			for (i = 0; i < sp->timecnt; ++i) {
  				j = sp->types[i];
  				sp->types[i] = sp->ttis[j].tt_isdst;
  				if (sp->ttis[j].tt_ttisgmt) {
  					/* No adjustment to transition time */
  				} else {
  					/*
  					** If summer time is in effect, and the
  					** transition time was not specified as
  					** standard time, add the summer time
  					** offset to the transition time;
  					** otherwise, add the standard time
  					** offset to the transition time.
  					*/
  					/*
  					** Transitions from DST to DDST
  					** will effectively disappear since
  					** POSIX provides for only one DST
  					** offset.
  					*/
  					if (isdst && !sp->ttis[j].tt_ttisstd) {
  						sp->ats[i] += dstoffset -
  							theirdstoffset;
  					} else {
  						sp->ats[i] += stdoffset -
  							theirstdoffset;
  					}
  				}
  				theiroffset = -sp->ttis[j].tt_gmtoff;
  				if (sp->ttis[j].tt_isdst)
  					theirdstoffset = theiroffset;
  				else	theirstdoffset = theiroffset;
  			}
  			/*
  			** Finally, fill in ttis.
  			** ttisstd and ttisgmt need not be handled.
  			*/
  			sp->ttis[0].tt_gmtoff = -stdoffset;
  			sp->ttis[0].tt_isdst = FALSE;
  			sp->ttis[0].tt_abbrind = 0;
  			sp->ttis[1].tt_gmtoff = -dstoffset;
  			sp->ttis[1].tt_isdst = TRUE;
  			sp->ttis[1].tt_abbrind = stdlen + 1;
  			sp->typecnt = 2;
  		}
  	} else {
  		dstlen = 0;
  		sp->typecnt = 1;		/* only standard time */
  		sp->timecnt = 0;
  		sp->ttis[0].tt_gmtoff = -stdoffset;
  		sp->ttis[0].tt_isdst = 0;
  		sp->ttis[0].tt_abbrind = 0;
  	}
  	sp->charcnt = stdlen + 1;
  	if (dstlen != 0)
  		sp->charcnt += dstlen + 1;
  	if ((size_t) sp->charcnt > sizeof sp->chars)
  		return -1;
  	cp = sp->chars;
  	(void) strncpy(cp, stdname, stdlen);
  	cp += stdlen;
  	*cp++ = '\0';
  	if (dstlen != 0) {
  		(void) strncpy(cp, dstname, dstlen);
  		*(cp + dstlen) = '\0';
  	}
  	return 0;
  }
  
  static void
  gmtload(sp)
  struct state * const	sp;
  {
  	if (tzload(gmt, sp, TRUE) != 0)
  		(void) tzparse(gmt, sp, TRUE);
  }
  
  #ifndef STD_INSPIRED
  /*
  ** A non-static declaration of tzsetwall in a system header file
  ** may cause a warning about this upcoming static declaration...
  */
  static
  #endif /* !defined STD_INSPIRED */
  void
  tzsetwall(void)
  {
  	if (lcl_is_set < 0)
  		return;
  	lcl_is_set = -1;
  
  #ifdef ALL_STATE
  	if (lclptr == NULL) {
  		lclptr = (struct state *) malloc(sizeof *lclptr);
  		if (lclptr == NULL) {
  			settzname();	/* all we can do */
  			return;
  		}
  	}
  #endif /* defined ALL_STATE */
  	if (tzload((char *) NULL, lclptr, TRUE) != 0)
  		gmtload(lclptr);
  	settzname();
  }
  
  void
  tzset(void)
  {
  	register const char *	name;
  
  	name = getenv("TZ");
  	if (name == NULL) {
  		tzsetwall();
  		return;
  	}
  
  	if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0)
  		return;
  	lcl_is_set = strlen(name) < sizeof lcl_TZname;
  	if (lcl_is_set)
  		(void) strcpy(lcl_TZname, name);
  
  #ifdef ALL_STATE
  	if (lclptr == NULL) {
  		lclptr = (struct state *) malloc(sizeof *lclptr);
  		if (lclptr == NULL) {
  			settzname();	/* all we can do */
  			return;
  		}
  	}
  #endif /* defined ALL_STATE */
  	if (*name == '\0') {
  		/*
  		** User wants it fast rather than right.
  		*/
  		lclptr->leapcnt = 0;		/* so, we're off a little */
  		lclptr->timecnt = 0;
  		lclptr->typecnt = 0;
  		lclptr->ttis[0].tt_isdst = 0;
  		lclptr->ttis[0].tt_gmtoff = 0;
  		lclptr->ttis[0].tt_abbrind = 0;
  		(void) strcpy(lclptr->chars, gmt);
  	} else if (tzload(name, lclptr, TRUE) != 0)
  		if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
  			(void) gmtload(lclptr);
  	settzname();
  }
  
  /*
  ** The easy way to behave "as if no library function calls" localtime
  ** is to not call it--so we drop its guts into "localsub", which can be
  ** freely called. (And no, the PANS doesn't require the above behavior--
  ** but it *is* desirable.)
  **
  ** The unused offset argument is for the benefit of mktime variants.
  */
  
  /*ARGSUSED*/
  static struct tm *
  localsub(timep, offset, tmp)
  const time_t * const	timep;
  const long		offset;
  struct tm * const	tmp;
  {
  	register struct state *		sp;
  	register const struct ttinfo *	ttisp;
  	register int			i;
  	register struct tm *		result;
  	const time_t			t = *timep;
  
  	sp = lclptr;
  #ifdef ALL_STATE
  	if (sp == NULL)
  		return gmtsub(timep, offset, tmp);
  #endif /* defined ALL_STATE */
  	if ((sp->goback && t < sp->ats[0]) ||
  		(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
  			time_t			newt = t;
  			register time_t		seconds;
  			register time_t		tcycles;
  			register int_fast64_t	icycles;
  
  			if (t < sp->ats[0])
  				seconds = sp->ats[0] - t;
  			else	seconds = t - sp->ats[sp->timecnt - 1];
  			--seconds;
  			tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
  			++tcycles;
  			icycles = tcycles;
  			if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
  				return NULL;
  			seconds = icycles;
  			seconds *= YEARSPERREPEAT;
  			seconds *= AVGSECSPERYEAR;
  			if (t < sp->ats[0])
  				newt += seconds;
  			else	newt -= seconds;
  			if (newt < sp->ats[0] ||
  				newt > sp->ats[sp->timecnt - 1])
  					return NULL;	/* "cannot happen" */
  			result = localsub(&newt, offset, tmp);
  			if (result == tmp) {
  				register time_t	newy;
  
  				newy = tmp->tm_year;
  				if (t < sp->ats[0])
  					newy -= icycles * YEARSPERREPEAT;
  				else	newy += icycles * YEARSPERREPEAT;
  				tmp->tm_year = newy;
  				if (tmp->tm_year != newy)
  					return NULL;
  			}
  			return result;
  	}
  	if (sp->timecnt == 0 || t < sp->ats[0]) {
  		i = 0;
  		while (sp->ttis[i].tt_isdst)
  			if (++i >= sp->typecnt) {
  				i = 0;
  				break;
  			}
  	} else {
  		register int	lo = 1;
  		register int	hi = sp->timecnt;
  
  		while (lo < hi) {
  			register int	mid = (lo + hi) >> 1;
  
  			if (t < sp->ats[mid])
  				hi = mid;
  			else	lo = mid + 1;
  		}
  		i = (int) sp->types[lo - 1];
  	}
  	ttisp = &sp->ttis[i];
  	/*
  	** To get (wrong) behavior that's compatible with System V Release 2.0
  	** you'd replace the statement below with
  	**	t += ttisp->tt_gmtoff;
  	**	timesub(&t, 0L, sp, tmp);
  	*/
  	result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
  	tmp->tm_isdst = ttisp->tt_isdst;
  	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
  #ifdef TM_ZONE
  	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
  #endif /* defined TM_ZONE */
  	return result;
  }
  
  struct tm *
  localtime(timep)
  const time_t * const	timep;
  {
  	tzset();
  	return localsub(timep, 0L, &tm);
  }
  
  /*
  ** Re-entrant version of localtime.
  */
  
  struct tm *
  localtime_r(timep, tmp)
  const time_t * const	timep;
  struct tm *		tmp;
  {
  	return localsub(timep, 0L, tmp);
  }
  
  /*
  ** gmtsub is to gmtime as localsub is to localtime.
  */
  
  static struct tm *
  gmtsub(timep, offset, tmp)
  const time_t * const	timep;
  const long		offset;
  struct tm * const	tmp;
  {
  	register struct tm *	result;
  
  	if (!gmt_is_set) {
  		gmt_is_set = TRUE;
  #ifdef ALL_STATE
  		gmtptr = (struct state *) malloc(sizeof *gmtptr);
  		if (gmtptr != NULL)
  #endif /* defined ALL_STATE */
  			gmtload(gmtptr);
  	}
  	result = timesub(timep, offset, gmtptr, tmp);
  #ifdef TM_ZONE
  	/*
  	** Could get fancy here and deliver something such as
  	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
  	** but this is no time for a treasure hunt.
  	*/
  	if (offset != 0)
  		tmp->TM_ZONE = wildabbr;
  	else {
  #ifdef ALL_STATE
  		if (gmtptr == NULL)
  			tmp->TM_ZONE = gmt;
  		else	tmp->TM_ZONE = gmtptr->chars;
  #endif /* defined ALL_STATE */
  #ifndef ALL_STATE
  		tmp->TM_ZONE = gmtptr->chars;
  #endif /* State Farm */
  	}
  #endif /* defined TM_ZONE */
  	return result;
  }
  
  struct tm *
  gmtime(timep)
  const time_t * const	timep;
  {
  	return gmtsub(timep, 0L, &tm);
  }
  
  /*
  * Re-entrant version of gmtime.
  */
  
  struct tm *
  gmtime_r(timep, tmp)
  const time_t * const	timep;
  struct tm *		tmp;
  {
  	return gmtsub(timep, 0L, tmp);
  }
  
  #ifdef STD_INSPIRED
  
  struct tm *
  offtime(timep, offset)
  const time_t * const	timep;
  const long		offset;
  {
  	return gmtsub(timep, offset, &tm);
  }
  
  #endif /* defined STD_INSPIRED */
  
  /*
  ** Return the number of leap years through the end of the given year
  ** where, to make the math easy, the answer for year zero is defined as zero.
  */
  
  static int
  leaps_thru_end_of(y)
  register const int	y;
  {
  	return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
  		-(leaps_thru_end_of(-(y + 1)) + 1);
  }
  
  static struct tm *
  timesub(timep, offset, sp, tmp)
  const time_t * const			timep;
  const long				offset;
  register const struct state * const	sp;
  register struct tm * const		tmp;
  {
  	register const struct lsinfo *	lp;
  	register time_t			tdays;
  	register int			idays;	/* unsigned would be so 2003 */
  	register long			rem;
  	int				y;
  	register const int *		ip;
  	register long			corr;
  	register int			hit;
  	register int			i;
  
  	corr = 0;
  	hit = 0;
  #ifdef ALL_STATE
  	i = (sp == NULL) ? 0 : sp->leapcnt;
  #endif /* defined ALL_STATE */
  #ifndef ALL_STATE
  	i = sp->leapcnt;
  #endif /* State Farm */
  	while (--i >= 0) {
  		lp = &sp->lsis[i];
  		if (*timep >= lp->ls_trans) {
  			if (*timep == lp->ls_trans) {
  				hit = ((i == 0 && lp->ls_corr > 0) ||
  					lp->ls_corr > sp->lsis[i - 1].ls_corr);
  				if (hit)
  					while (i > 0 &&
  						sp->lsis[i].ls_trans ==
  						sp->lsis[i - 1].ls_trans + 1 &&
  						sp->lsis[i].ls_corr ==
  						sp->lsis[i - 1].ls_corr + 1) {
  							++hit;
  							--i;
  					}
  			}
  			corr = lp->ls_corr;
  			break;
  		}
  	}
  	y = EPOCH_YEAR;
  	tdays = *timep / SECSPERDAY;
  	rem = *timep - tdays * SECSPERDAY;
  	while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
  		int		newy;
  		register time_t	tdelta;
  		register int	idelta;
  		register int	leapdays;
  
  		tdelta = tdays / DAYSPERLYEAR;
  		idelta = tdelta;
  		if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
  			return NULL;
  		if (idelta == 0)
  			idelta = (tdays < 0) ? -1 : 1;
  		newy = y;
  		if (increment_overflow(&newy, idelta))
  			return NULL;
  		leapdays = leaps_thru_end_of(newy - 1) -
  			leaps_thru_end_of(y - 1);
  		tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
  		tdays -= leapdays;
  		y = newy;
  	}
  	{
  		register long	seconds;
  
  		seconds = tdays * SECSPERDAY + 0.5;
  		tdays = seconds / SECSPERDAY;
  		rem += seconds - tdays * SECSPERDAY;
  	}
  	/*
  	** Given the range, we can now fearlessly cast...
  	*/
  	idays = tdays;
  	rem += offset - corr;
  	while (rem < 0) {
  		rem += SECSPERDAY;
  		--idays;
  	}
  	while (rem >= SECSPERDAY) {
  		rem -= SECSPERDAY;
  		++idays;
  	}
  	while (idays < 0) {
  		if (increment_overflow(&y, -1))
  			return NULL;
  		idays += year_lengths[isleap(y)];
  	}
  	while (idays >= year_lengths[isleap(y)]) {
  		idays -= year_lengths[isleap(y)];
  		if (increment_overflow(&y, 1))
  			return NULL;
  	}
  	tmp->tm_year = y;
  	if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
  		return NULL;
  	tmp->tm_yday = idays;
  	/*
  	** The "extra" mods below avoid overflow problems.
  	*/
  	tmp->tm_wday = EPOCH_WDAY +
  		((y - EPOCH_YEAR) % DAYSPERWEEK) *
  		(DAYSPERNYEAR % DAYSPERWEEK) +
  		leaps_thru_end_of(y - 1) -
  		leaps_thru_end_of(EPOCH_YEAR - 1) +
  		idays;
  	tmp->tm_wday %= DAYSPERWEEK;
  	if (tmp->tm_wday < 0)
  		tmp->tm_wday += DAYSPERWEEK;
  	tmp->tm_hour = (int) (rem / SECSPERHOUR);
  	rem %= SECSPERHOUR;
  	tmp->tm_min = (int) (rem / SECSPERMIN);
  	/*
  	** A positive leap second requires a special
  	** representation. This uses "... ??:59:60" et seq.
  	*/
  	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
  	ip = mon_lengths[isleap(y)];
  	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
  		idays -= ip[tmp->tm_mon];
  	tmp->tm_mday = (int) (idays + 1);
  	tmp->tm_isdst = 0;
  #ifdef TM_GMTOFF
  	tmp->TM_GMTOFF = offset;
  #endif /* defined TM_GMTOFF */
  	return tmp;
  }
  
  char *
  ctime(timep)
  const time_t * const	timep;
  {
  /*
  ** Section 4.12.3.2 of X3.159-1989 requires that
  **	The ctime function converts the calendar time pointed to by timer
  **	to local time in the form of a string. It is equivalent to
  **		asctime(localtime(timer))
  */
  	return asctime(localtime(timep));
  }
  
  char *
  ctime_r(timep, buf)
  const time_t * const	timep;
  char *			buf;
  {
  	struct tm	mytm;
  
  	return asctime_r(localtime_r(timep, &mytm), buf);
  }
  
  /*
  ** Adapted from code provided by Robert Elz, who writes:
  **	The "best" way to do mktime I think is based on an idea of Bob
  **	Kridle's (so its said...) from a long time ago.
  **	It does a binary search of the time_t space. Since time_t's are
  **	just 32 bits, its a max of 32 iterations (even at 64 bits it
  **	would still be very reasonable).
  */
  
  #ifndef WRONG
  #define WRONG	(-1)
  #endif /* !defined WRONG */
  
  /*
  ** Simplified normalize logic courtesy Paul Eggert.
  */
  
  static int
  increment_overflow(number, delta)
  int *	number;
  int	delta;
  {
  	int	number0;
  
  	number0 = *number;
  	*number += delta;
  	return (*number < number0) != (delta < 0);
  }
  
  static int
  long_increment_overflow(number, delta)
  long *	number;
  int	delta;
  {
  	long	number0;
  
  	number0 = *number;
  	*number += delta;
  	return (*number < number0) != (delta < 0);
  }
  
  static int
  normalize_overflow(tensptr, unitsptr, base)
  int * const	tensptr;
  int * const	unitsptr;
  const int	base;
  {
  	register int	tensdelta;
  
  	tensdelta = (*unitsptr >= 0) ?
  		(*unitsptr / base) :
  		(-1 - (-1 - *unitsptr) / base);
  	*unitsptr -= tensdelta * base;
  	return increment_overflow(tensptr, tensdelta);
  }
  
  static int
  long_normalize_overflow(tensptr, unitsptr, base)
  long * const	tensptr;
  int * const	unitsptr;
  const int	base;
  {
  	register int	tensdelta;
  
  	tensdelta = (*unitsptr >= 0) ?
  		(*unitsptr / base) :
  		(-1 - (-1 - *unitsptr) / base);
  	*unitsptr -= tensdelta * base;
  	return long_increment_overflow(tensptr, tensdelta);
  }
  
  static int
  tmcomp(atmp, btmp)
  register const struct tm * const atmp;
  register const struct tm * const btmp;
  {
  	register int	result;
  
  	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
  		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
  		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
  		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
  		(result = (atmp->tm_min - btmp->tm_min)) == 0)
  			result = atmp->tm_sec - btmp->tm_sec;
  	return result;
  }
  
  static time_t
  time2sub(tmp, funcp, offset, okayp, do_norm_secs)
  struct tm * const	tmp;
  struct tm * (* const	funcp)(const time_t*, long, struct tm*);
  const long		offset;
  int * const		okayp;
  const int		do_norm_secs;
  {
  	register const struct state *	sp;
  	register int			dir;
  	register int			i, j;
  	register int			saved_seconds;
  	register long			li;
  	register time_t			lo;
  	register time_t			hi;
  	long				y;
  	time_t				newt;
  	time_t				t;
  	struct tm			yourtm, mytm;
  
  	*okayp = FALSE;
  	yourtm = *tmp;
  	if (do_norm_secs) {
  		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
  			SECSPERMIN))
  				return WRONG;
  	}
  	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
  		return WRONG;
  	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
  		return WRONG;
  	y = yourtm.tm_year;
  	if (long_normalize_overflow(&y, &yourtm.tm_mon, MONSPERYEAR))
  		return WRONG;
  	/*
  	** Turn y into an actual year number for now.
  	** It is converted back to an offset from TM_YEAR_BASE later.
  	*/
  	if (long_increment_overflow(&y, TM_YEAR_BASE))
  		return WRONG;
  	while (yourtm.tm_mday <= 0) {
  		if (long_increment_overflow(&y, -1))
  			return WRONG;
  		li = y + (1 < yourtm.tm_mon);
  		yourtm.tm_mday += year_lengths[isleap(li)];
  	}
  	while (yourtm.tm_mday > DAYSPERLYEAR) {
  		li = y + (1 < yourtm.tm_mon);
  		yourtm.tm_mday -= year_lengths[isleap(li)];
  		if (long_increment_overflow(&y, 1))
  			return WRONG;
  	}
  	for ( ; ; ) {
  		i = mon_lengths[isleap(y)][yourtm.tm_mon];
  		if (yourtm.tm_mday <= i)
  			break;
  		yourtm.tm_mday -= i;
  		if (++yourtm.tm_mon >= MONSPERYEAR) {
  			yourtm.tm_mon = 0;
  			if (long_increment_overflow(&y, 1))
  				return WRONG;
  		}
  	}
  	if (long_increment_overflow(&y, -TM_YEAR_BASE))
  		return WRONG;
  	yourtm.tm_year = y;
  	if (yourtm.tm_year != y)
  		return WRONG;
  	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
  		saved_seconds = 0;
  	else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
  		/*
  		** We can't set tm_sec to 0, because that might push the
  		** time below the minimum representable time.
  		** Set tm_sec to 59 instead.
  		** This assumes that the minimum representable time is
  		** not in the same minute that a leap second was deleted from,
  		** which is a safer assumption than using 58 would be.
  		*/
  		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
  			return WRONG;
  		saved_seconds = yourtm.tm_sec;
  		yourtm.tm_sec = SECSPERMIN - 1;
  	} else {
  		saved_seconds = yourtm.tm_sec;
  		yourtm.tm_sec = 0;
  	}
  	/*
  	** Do a binary search (this works whatever time_t's type is).
  	*/
  	if (!TYPE_SIGNED(time_t)) {
  		lo = 0;
  		hi = lo - 1;
  	} else if (!TYPE_INTEGRAL(time_t)) {
  		if (sizeof(time_t) > sizeof(float))
  			hi = (time_t) DBL_MAX;
  		else	hi = (time_t) FLT_MAX;
  		lo = -hi;
  	} else {
  		lo = 1;
  		for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
  			lo *= 2;
  		hi = -(lo + 1);
  	}
  	for ( ; ; ) {
  		t = lo / 2 + hi / 2;
  		if (t < lo)
  			t = lo;
  		else if (t > hi)
  			t = hi;
  		if ((*funcp)(&t, offset, &mytm) == NULL) {
  			/*
  			** Assume that t is too extreme to be represented in
  			** a struct tm; arrange things so that it is less
  			** extreme on the next pass.
  			*/
  			dir = (t > 0) ? 1 : -1;
  		} else	dir = tmcomp(&mytm, &yourtm);
  		if (dir != 0) {
  			if (t == lo) {
  				++t;
  				if (t <= lo)
  					return WRONG;
  				++lo;
  			} else if (t == hi) {
  				--t;
  				if (t >= hi)
  					return WRONG;
  				--hi;
  			}
  			if (lo > hi)
  				return WRONG;
  			if (dir > 0)
  				hi = t;
  			else	lo = t;
  			continue;
  		}
  		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
  			break;
  		/*
  		** Right time, wrong type.
  		** Hunt for right time, right type.
  		** It's okay to guess wrong since the guess
  		** gets checked.
  		*/
  		sp = (const struct state *)
  			((funcp == localsub) ? lclptr : gmtptr);
  #ifdef ALL_STATE
  		if (sp == NULL)
  			return WRONG;
  #endif /* defined ALL_STATE */
  		for (i = sp->typecnt - 1; i >= 0; --i) {
  			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
  				continue;
  			for (j = sp->typecnt - 1; j >= 0; --j) {
  				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
  					continue;
  				newt = t + sp->ttis[j].tt_gmtoff -
  					sp->ttis[i].tt_gmtoff;
  				if ((*funcp)(&newt, offset, &mytm) == NULL)
  					continue;
  				if (tmcomp(&mytm, &yourtm) != 0)
  					continue;
  				if (mytm.tm_isdst != yourtm.tm_isdst)
  					continue;
  				/*
  				** We have a match.
  				*/
  				t = newt;
  				goto label;
  			}
  		}
  		return WRONG;
  	}
  label:
  	newt = t + saved_seconds;
  	if ((newt < t) != (saved_seconds < 0))
  		return WRONG;
  	t = newt;
  	if ((*funcp)(&t, offset, tmp))
  		*okayp = TRUE;
  	return t;
  }
  
  static time_t
  time2(tmp, funcp, offset, okayp)
  struct tm * const	tmp;
  struct tm * (* const	funcp)(const time_t*, long, struct tm*);
  const long		offset;
  int * const		okayp;
  {
  	time_t	t;
  
  	/*
  	** First try without normalization of seconds
  	** (in case tm_sec contains a value associated with a leap second).
  	** If that fails, try with normalization of seconds.
  	*/
  	t = time2sub(tmp, funcp, offset, okayp, FALSE);
  	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE);
  }
  
  static time_t
  time1(tmp, funcp, offset)
  struct tm * const	tmp;
  struct tm * (* const	funcp)(const time_t *, long, struct tm *);
  const long		offset;
  {
  	register time_t			t;
  	register const struct state *	sp;
  	register int			samei, otheri;
  	register int			sameind, otherind;
  	register int			i;
  	register int			nseen;
  	int				seen[TZ_MAX_TYPES];
  	int				types[TZ_MAX_TYPES];
  	int				okay;
  
  	if (tmp->tm_isdst > 1)
  		tmp->tm_isdst = 1;
  	t = time2(tmp, funcp, offset, &okay);
  #ifdef PCTS
  	/*
  	** PCTS code courtesy Grant Sullivan.
  	*/
  	if (okay)
  		return t;
  	if (tmp->tm_isdst < 0)
  		tmp->tm_isdst = 0;	/* reset to std and try again */
  #endif /* defined PCTS */
  #ifndef PCTS
  	if (okay || tmp->tm_isdst < 0)
  		return t;
  #endif /* !defined PCTS */
  	/*
  	** We're supposed to assume that somebody took a time of one type
  	** and did some math on it that yielded a "struct tm" that's bad.
  	** We try to divine the type they started from and adjust to the
  	** type they need.
  	*/
  	sp = (const struct state *) ((funcp == localsub) ?  lclptr : gmtptr);
  #ifdef ALL_STATE
  	if (sp == NULL)
  		return WRONG;
  #endif /* defined ALL_STATE */
  	for (i = 0; i < sp->typecnt; ++i)
  		seen[i] = FALSE;
  	nseen = 0;
  	for (i = sp->timecnt - 1; i >= 0; --i)
  		if (!seen[sp->types[i]]) {
  			seen[sp->types[i]] = TRUE;
  			types[nseen++] = sp->types[i];
  		}
  	for (sameind = 0; sameind < nseen; ++sameind) {
  		samei = types[sameind];
  		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
  			continue;
  		for (otherind = 0; otherind < nseen; ++otherind) {
  			otheri = types[otherind];
  			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
  				continue;
  			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
  					sp->ttis[samei].tt_gmtoff;
  			tmp->tm_isdst = !tmp->tm_isdst;
  			t = time2(tmp, funcp, offset, &okay);
  			if (okay)
  				return t;
  			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
  					sp->ttis[samei].tt_gmtoff;
  			tmp->tm_isdst = !tmp->tm_isdst;
  		}
  	}
  	return WRONG;
  }
  
  time_t
  mktime(tmp)
  struct tm * const	tmp;
  {
  	tzset();
  	return time1(tmp, localsub, 0L);
  }
  
  #ifdef STD_INSPIRED
  
  time_t
  timelocal(tmp)
  struct tm * const	tmp;
  {
  	tmp->tm_isdst = -1;	/* in case it wasn't initialized */
  	return mktime(tmp);
  }
  
  time_t
  timegm(tmp)
  struct tm * const	tmp;
  {
  	tmp->tm_isdst = 0;
  	return time1(tmp, gmtsub, 0L);
  }
  
  time_t
  timeoff(tmp, offset)
  struct tm * const	tmp;
  const long		offset;
  {
  	tmp->tm_isdst = 0;
  	return time1(tmp, gmtsub, offset);
  }
  
  #endif /* defined STD_INSPIRED */
  
  #ifdef CMUCS
  
  /*
  ** The following is supplied for compatibility with
  ** previous versions of the CMUCS runtime library.
  */
  
  long
  gtime(tmp)
  struct tm * const	tmp;
  {
  	const time_t	t = mktime(tmp);
  
  	if (t == WRONG)
  		return -1;
  	return t;
  }
  
  #endif /* defined CMUCS */
  
  /*
  ** XXX--is the below the right way to conditionalize??
  */
  
  #ifdef STD_INSPIRED
  
  /*
  ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
  ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
  ** is not the case if we are accounting for leap seconds.
  ** So, we provide the following conversion routines for use
  ** when exchanging timestamps with POSIX conforming systems.
  */
  
  static long
  leapcorr(timep)
  time_t *	timep;
  {
  	register struct state *		sp;
  	register struct lsinfo *	lp;
  	register int			i;
  
  	sp = lclptr;
  	i = sp->leapcnt;
  	while (--i >= 0) {
  		lp = &sp->lsis[i];
  		if (*timep >= lp->ls_trans)
  			return lp->ls_corr;
  	}
  	return 0;
  }
  
  time_t
  time2posix(t)
  time_t	t;
  {
  	tzset();
  	return t - leapcorr(&t);
  }
  
  time_t
  posix2time(t)
  time_t	t;
  {
  	time_t	x;
  	time_t	y;
  
  	tzset();
  	/*
  	** For a positive leap second hit, the result
  	** is not unique. For a negative leap second
  	** hit, the corresponding time doesn't exist,
  	** so we return an adjacent second.
  	*/
  	x = t + leapcorr(&t);
  	y = x - leapcorr(&x);
  	if (y < t) {
  		do {
  			x++;
  			y = x - leapcorr(&x);
  		} while (y < t);
  		if (t != y)
  			return x - 1;
  	} else if (y > t) {
  		do {
  			--x;
  			y = x - leapcorr(&x);
  		} while (y > t);
  		if (t != y)
  			return x + 1;
  	}
  	return x;
  }
  
  #endif /* defined STD_INSPIRED */
  