%token ID MONTH DAY MERIDIAN NUMBER UNIT MUNIT SUNIT ZONE DAYZONE AGO
%{
	/* 	Steven M. Bellovin (unc!smb)			*/
	/*	Dept. of Computer Science			*/
	/*	University of North Carolina at Chapel Hill	*/
	/*	@(#)getdate.y	2.13	9/16/86 */

#include <stdio.h>
#include <sys/types.h>
#include <ctype.h>
#include <time.h>
#define	timezone	tmzn	/* ugly hack for obscure name clash */
#include <sys/timeb.h>

#define daysec (24L*60L*60L)

	static int timeflag, zoneflag, dateflag, dayflag, relflag;
	static time_t relsec, relmonth;
	static int hh, mm, ss, merid, daylight;
	static int dayord, dayreq;
	static int month, day, year;
	static int ourzone;

#define AM 1
#define PM 2
#define DAYLIGHT 1
#define STANDARD 2
#define MAYBE    3
%}

%%
timedate: 		/* empty */
	| timedate item;

item:	tspec =
		{timeflag++;}
	| zone =
		{zoneflag++;}
	| dtspec =
		{dateflag++;}
	| dyspec =
		{dayflag++;}
	| rspec =
		{relflag++;}
	| nspec;

nspec:	NUMBER =
		{if (timeflag && dateflag && !relflag) year = $1;
		else {timeflag++;hh = $1/100;mm = $1%100;ss = 0;merid = 24;}};

tspec:	NUMBER MERIDIAN =
		{hh = $1; mm = 0; ss = 0; merid = $2;}
	| NUMBER ':' NUMBER =
		{hh = $1; mm = $3; merid = 24;}
	| NUMBER ':' NUMBER MERIDIAN =
		{hh = $1; mm = $3; merid = $4;}
	| NUMBER ':' NUMBER NUMBER =
		{hh = $1; mm = $3; merid = 24;
		daylight = STANDARD; ourzone = $4%100 + 60*$4/100;}
	| NUMBER ':' NUMBER ':' NUMBER =
		{hh = $1; mm = $3; ss = $5; merid = 24;}
	| NUMBER ':' NUMBER ':' NUMBER MERIDIAN =
		{hh = $1; mm = $3; ss = $5; merid = $6;}
	| NUMBER ':' NUMBER ':' NUMBER NUMBER =
		{hh = $1; mm = $3; ss = $5; merid = 24;
		daylight = STANDARD; ourzone = $6%100 + 60*$6/100;};

zone:	ZONE =
		{ourzone = $1; daylight = STANDARD;}
	| DAYZONE =
		{ourzone = $1; daylight = DAYLIGHT;};

dyspec:	DAY =
		{dayord = 1; dayreq = $1;}
	| DAY ',' =
		{dayord = 1; dayreq = $1;}
	| NUMBER DAY =
		{dayord = $1; dayreq = $2;};

dtspec:	NUMBER '/' NUMBER =
		{month = $1; day = $3;}
	| NUMBER '/' NUMBER '/' NUMBER =
		{month = $1; day = $3; year = $5;}
	| MONTH NUMBER =
		{month = $1; day = $2;}
	| MONTH NUMBER ',' NUMBER =
		{month = $1; day = $2; year = $4;}
	| NUMBER MONTH =
		{month = $2; day = $1;}
	| NUMBER MONTH NUMBER =
		{month = $2; day = $1; year = $3;};


rspec:	NUMBER UNIT =
		{relsec +=  60L * $1 * $2;}
	| NUMBER MUNIT =
		{relmonth += $1 * $2;}
	| NUMBER SUNIT =
		{relsec += $1;}
	| UNIT =
		{relsec +=  60L * $1;}
	| MUNIT =
		{relmonth += $1;}
	| SUNIT =
		{relsec++;}
	| rspec AGO =
		{relsec = -relsec; relmonth = -relmonth;};
%%

static int mdays[12] =
	{31, 0, 31,  30, 31, 30,  31, 31, 30,  31, 30, 31};
#define epoch 1970

extern struct tm *localtime();

static time_t
dateconv(mm, dd, yy, h, m, s, mer, zone, dayflag)
int mm, dd, yy, h, m, s, mer, zone, dayflag;
{
	time_t tod, jdate;
	register int i;
	time_t timeconv();

	if (yy < 0) yy = -yy;
	if (yy < 100) yy += 1900;
	mdays[1] = 28 + (yy%4 == 0 && (yy%100 != 0 || yy%400 == 0));
	if (yy < epoch || yy > 1999 || mm < 1 || mm > 12 ||
		dd < 1 || dd > mdays[--mm]) return (-1);
	jdate = dd-1;
        for (i=0; i<mm; i++) jdate += mdays[i];
	for (i = epoch; i < yy; i++) jdate += 365 + (i%4 == 0);
	jdate *= daysec;
	jdate += zone * 60L;
	if ((tod = timeconv(h, m, s, mer)) < 0) return (-1);
	jdate += tod;
	if (dayflag==DAYLIGHT || (dayflag==MAYBE&&localtime(&jdate)->tm_isdst))
		jdate += -1*60*60;
	return (jdate);
}

static time_t
dayconv(ord, day, now)
int ord, day; time_t now;
{
	register struct tm *loctime;
	time_t tod;
	time_t daylcorr();

	tod = now;
	loctime = localtime(&tod);
	tod += daysec * ((day - loctime->tm_wday + 7) % 7);
	tod += 7*daysec*(ord<=0?ord:ord-1);
	return daylcorr(tod, now);
}

static time_t
timeconv(hh, mm, ss, mer)
register int hh, mm, ss, mer;
{
	if (mm < 0 || mm > 59 || ss < 0 || ss > 59) return (-1);
	switch (mer) {
		case AM: if (hh < 1 || hh > 12) return(-1);
			 return (60L * ((hh%12)*60L + mm)+ss);
		case PM: if (hh < 1 || hh > 12) return(-1);
			 return (60L * ((hh%12 +12)*60L + mm)+ss);
		case 24: if (hh < 0 || hh > 23) return (-1);
			 return (60L * (hh*60L + mm)+ss);
		default: return (-1);
	}
}

static time_t
monthadd(sdate, relmonth)
time_t sdate, relmonth;
{
	struct tm *ltime;
	time_t dateconv();
	time_t daylcorr();
	int mm, yy;

	if (relmonth == 0) return 0;
	ltime = localtime(&sdate);
	mm = 12*ltime->tm_year + ltime->tm_mon + relmonth;
	yy = mm/12;
	mm = mm%12 + 1;
	return daylcorr(dateconv(mm, ltime->tm_mday, yy, ltime->tm_hour,
		ltime->tm_min, ltime->tm_sec, 24, ourzone, MAYBE), sdate);
}

static time_t
daylcorr(future, now)
time_t future, now;
{
	int fdayl, nowdayl;

	nowdayl = (localtime(&now)->tm_hour+1) % 24;
	fdayl = (localtime(&future)->tm_hour+1) % 24;
	return (future-now) + 60L*60L*(nowdayl-fdayl);
}

static char *lptr;

yylex()
{
	extern int yylval;
	int sign;
	register char c;
	register char *p;
	char idbuf[20];
	int pcnt;

	for (;;) {
		while (isspace(*lptr)) lptr++;

		if (isdigit(c = *lptr) || c == '-' || c == '+') {
			if (c== '-' || c == '+') {
				if (c=='-') sign = -1;
				else sign = 1;
				if (!isdigit(*++lptr)) {
					/* yylval = sign; return (NUMBER); */
					return yylex();	/* skip the '-' sign */
				}
			} else sign = 1;
			yylval = 0;
			while (isdigit(c = *lptr++)) yylval = 10*yylval + c - '0';
			yylval *= sign;
			lptr--;
			return (NUMBER);

		} else if (isalpha(c)) {
			p = idbuf;
			while (isalpha(c = *lptr++) || c=='.')
				if (p < &idbuf[sizeof(idbuf)-1])
					*p++ = c;
			*p = '\0';
			lptr--;
			return (lookup(idbuf));
		}

		else if (c == '(') {
			pcnt = 0;
			do {
				c = *lptr++;
				if (c == '\0') return(c);
				else if (c == '(') pcnt++;
				else if (c == ')') pcnt--;
			} while (pcnt > 0);
		}

		else return (*lptr++);
	}
}

struct table {
	char *name;
	int type, value;
};

static struct table mdtab[] = {
	{"January", MONTH, 1},
	{"February", MONTH, 2},
	{"March", MONTH, 3},
	{"April", MONTH, 4},
	{"May", MONTH, 5},
	{"June", MONTH, 6},
	{"July", MONTH, 7},
	{"August", MONTH, 8},
	{"September", MONTH, 9},
	{"Sept", MONTH, 9},
	{"October", MONTH, 10},
	{"November", MONTH, 11},
	{"December", MONTH, 12},

	{"Sunday", DAY, 0},
	{"Monday", DAY, 1},
	{"Tuesday", DAY, 2},
	{"Tues", DAY, 2},
	{"Wednesday", DAY, 3},
	{"Wednes", DAY, 3},
	{"Thursday", DAY, 4},
	{"Thur", DAY, 4},
	{"Thurs", DAY, 4},
	{"Friday", DAY, 5},
	{"Saturday", DAY, 6},
	{0, 0, 0}};

#define HRS *60
#define HALFHR 30
static struct table mztab[] = {
	{"a.m.", MERIDIAN, AM},
	{"am", MERIDIAN, AM},
	{"p.m.", MERIDIAN, PM},
	{"pm", MERIDIAN, PM},
	{"nst", ZONE, 3 HRS + HALFHR},		/* Newfoundland */
	{"n.s.t.", ZONE, 3 HRS + HALFHR},
	{"ast", ZONE, 4 HRS},		/* Atlantic */
	{"a.s.t.", ZONE, 4 HRS},
	{"adt", DAYZONE, 4 HRS},
	{"a.d.t.", DAYZONE, 4 HRS},
	{"est", ZONE, 5 HRS},		/* Eastern */
	{"e.s.t.", ZONE, 5 HRS},
	{"edt", DAYZONE, 5 HRS},
	{"e.d.t.", DAYZONE, 5 HRS},
	{"cst", ZONE, 6 HRS},		/* Central */
	{"c.s.t.", ZONE, 6 HRS},
	{"cdt", DAYZONE, 6 HRS},
	{"c.d.t.", DAYZONE, 6 HRS},
	{"mst", ZONE, 7 HRS},		/* Mountain */
	{"m.s.t.", ZONE, 7 HRS},
	{"mdt", DAYZONE, 7 HRS},
	{"m.d.t.", DAYZONE, 7 HRS},
	{"pst", ZONE, 8 HRS},		/* Pacific */
	{"p.s.t.", ZONE, 8 HRS},
	{"pdt", DAYZONE, 8 HRS},
	{"p.d.t.", DAYZONE, 8 HRS},
	{"yst", ZONE, 9 HRS},		/* Yukon */
	{"y.s.t.", ZONE, 9 HRS},
	{"ydt", DAYZONE, 9 HRS},
	{"y.d.t.", DAYZONE, 9 HRS},
	{"hst", ZONE, 10 HRS},		/* Hawaii */
	{"h.s.t.", ZONE, 10 HRS},
	{"hdt", DAYZONE, 10 HRS},
	{"h.d.t.", DAYZONE, 10 HRS},

	{"gmt", ZONE, 0 HRS},
	{"g.m.t.", ZONE, 0 HRS},
	{"ut", ZONE, 0 HRS},
	{"u.t.", ZONE, 0 HRS},
	{"bst", DAYZONE, 0 HRS},		/* British Summer Time */
	{"b.s.t.", DAYZONE, 0 HRS},
	{"eet", ZONE, 0 HRS},		/* European Eastern Time */
	{"e.e.t.", ZONE, 0 HRS},
	{"eest", DAYZONE, 0 HRS},	/* European Eastern Summer Time */
	{"e.e.s.t.", DAYZONE, 0 HRS},
	{"met", ZONE, -1 HRS},		/* Middle European Time */
	{"m.e.t.", ZONE, -1 HRS},
	{"mest", DAYZONE, -1 HRS},	/* Middle European Summer Time */
	{"m.e.s.t.", DAYZONE, -1 HRS},
	{"wet", ZONE, -2 HRS },		/* Western European Time */
	{"w.e.t.", ZONE, -2 HRS },
	{"west", DAYZONE, -2 HRS},	/* Western European Summer Time */
	{"w.e.s.t.", DAYZONE, -2 HRS},

	{"jst", ZONE, -9 HRS},		/* Japan Standard Time */
	{"j.s.t.", ZONE, -9 HRS},	/* Japan Standard Time */
					/* No daylight savings time */

	{"aest", ZONE, -10 HRS},	/* Australian Eastern Time */
	{"a.e.s.t.", ZONE, -10 HRS},
	{"aesst", DAYZONE, -10 HRS},	/* Australian Eastern Summer Time */
	{"a.e.s.s.t.", DAYZONE, -10 HRS},
	{"acst", ZONE, -(9 HRS + HALFHR)},	/* Australian Central Time */
	{"a.c.s.t.", ZONE, -(9 HRS + HALFHR)},
	{"acsst", DAYZONE, -(9 HRS + HALFHR)},	/* Australian Central Summer */
	{"a.c.s.s.t.", DAYZONE, -(9 HRS + HALFHR)},
	{"awst", ZONE, -8 HRS},		/* Australian Western Time */
	{"a.w.s.t.", ZONE, -8 HRS},	/* (no daylight time there, I'm told */
	{0, 0, 0}};

static struct table unittb[] = {
	{"year", MUNIT, 12},
	{"month", MUNIT, 1},
	{"fortnight", UNIT, 14*24*60},
	{"week", UNIT, 7*24*60},
	{"day", UNIT, 1*24*60},
	{"hour", UNIT, 60},
	{"minute", UNIT, 1},
	{"min", UNIT, 1},
	{"second", SUNIT, 1},
	{"sec", SUNIT, 1},
	{0, 0, 0}};

static struct table othertb[] = {
	{"tomorrow", UNIT, 1*24*60},
	{"yesterday", UNIT, -1*24*60},
	{"today", UNIT, 0},
	{"now", UNIT, 0},
	{"last", NUMBER, -1},
	{"this", UNIT, 0},
	{"next", NUMBER, 2},
	{"first", NUMBER, 1},
	/* {"second", NUMBER, 2}, */
	{"third", NUMBER, 3},
	{"fourth", NUMBER, 4},
	{"fifth", NUMBER, 5},
	{"sixth", NUMBER, 6},
	{"seventh", NUMBER, 7},
	{"eigth", NUMBER, 8},
	{"ninth", NUMBER, 9},
	{"tenth", NUMBER, 10},
	{"eleventh", NUMBER, 11},
	{"twelfth", NUMBER, 12},
	{"ago", AGO, 1},
	{0, 0, 0}};

static struct table milzone[] = {
	{"a", ZONE, 1 HRS},
	{"b", ZONE, 2 HRS},
	{"c", ZONE, 3 HRS},
	{"d", ZONE, 4 HRS},
	{"e", ZONE, 5 HRS},
	{"f", ZONE, 6 HRS},
	{"g", ZONE, 7 HRS},
	{"h", ZONE, 8 HRS},
	{"i", ZONE, 9 HRS},
	{"k", ZONE, 10 HRS},
	{"l", ZONE, 11 HRS},
	{"m", ZONE, 12 HRS},
	{"n", ZONE, -1 HRS},
	{"o", ZONE, -2 HRS},
	{"p", ZONE, -3 HRS},
	{"q", ZONE, -4 HRS},
	{"r", ZONE, -5 HRS},
	{"s", ZONE, -6 HRS},
	{"t", ZONE, -7 HRS},
	{"u", ZONE, -8 HRS},
	{"v", ZONE, -9 HRS},
	{"w", ZONE, -10 HRS},
	{"x", ZONE, -11 HRS},
	{"y", ZONE, -12 HRS},
	{"z", ZONE, 0 HRS},
	{0, 0, 0}};

static
lookup(id)
char *id;
{
#define gotit (yylval=i->value,  i->type)
#define getid for(j=idvar, k=id; *j++ = *k++; )

	char idvar[20];
	register char *j, *k;
	register struct table *i;
	int abbrev;

	getid;
	if (strlen(idvar) == 3) abbrev = 1;
	else if (strlen(idvar) == 4 && idvar[3] == '.') {
		abbrev = 1;
		idvar[3] = '\0';
	}
	else abbrev = 0;

	if (islower(*idvar)) *idvar = toupper(*idvar);

	for (i = mdtab; i->name; i++) {
		k = idvar;
		for (j = i->name; *j++ == *k++;) {
			if (abbrev && j==i->name+3) return gotit;
			if (j[-1] == 0) return gotit;
		}
	}

	getid;
	for (i = mztab; i->name; i++)
		if (strcmp(i->name, idvar) == 0) return gotit;

	for (j = idvar; *j; j++)
		if (isupper(*j)) *j = tolower(*j);
	for (i=mztab; i->name; i++)
		if (strcmp(i->name, idvar) == 0) return gotit;

	getid;
	for (i=unittb; i->name; i++)
		if (strcmp(i->name, idvar) == 0) return gotit;

	if (idvar[strlen(idvar)-1] == 's')
		idvar[strlen(idvar)-1] = '\0';
	for (i=unittb; i->name; i++)
		if (strcmp(i->name, idvar) == 0) return gotit;

	getid;
	for (i = othertb; i->name; i++)
		if (strcmp(i->name, idvar) == 0) return gotit;

	getid;
	if (strlen(idvar) == 1 && isalpha(*idvar)) {
		if (isupper(*idvar)) *idvar = tolower(*idvar);
		for (i = milzone; i->name; i++)
			if (strcmp(i->name, idvar) == 0) return gotit;
	}

	return(ID);
}

time_t
getdate(p, now)
char *p;
struct timeb *now;
{
#define mcheck(f)	if (f>1) err++
	time_t monthadd();
	int err;
	struct tm *lt;
	struct timeb ftz;

	time_t sdate, tod;

	lptr = p;
	if (now == ((struct timeb *) NULL)) {
		now = &ftz;
		ftime(&ftz);
	}
	lt = localtime(&now->time);
	year = lt->tm_year;
	month = lt->tm_mon+1;
	day = lt->tm_mday;
	relsec = 0; relmonth = 0;
	timeflag=zoneflag=dateflag=dayflag=relflag=0;
	ourzone = now->timezone;
	daylight = MAYBE;
	hh = mm = ss = 0;
	merid = 24;

	if (err = yyparse()) return (-1);

	mcheck(timeflag);
	mcheck(zoneflag);
	mcheck(dateflag);
	mcheck(dayflag);

	if (err) return (-1);
	if (dateflag || timeflag || dayflag) {
		sdate = dateconv(month,day,year,hh,mm,ss,merid,ourzone,daylight);
		if (sdate < 0) return -1;
	}
	else {
		sdate = now->time;
		if (relflag == 0)
			sdate -= (lt->tm_sec + lt->tm_min*60 +
				lt->tm_hour*(60L*60L));
	}

	sdate += relsec;
	sdate += monthadd(sdate, relmonth);

	if (dayflag && !dateflag) {
		tod = dayconv(dayord, dayreq, sdate);
		sdate += tod;
	}

	return sdate;
}

yyerror(s) char *s;
{}
