+#
+/*
+ * This routine converts time as follows.
+ * The epoch is 0000 Jan 1 1970 GMT.
+ * The argument time is in seconds since then.
+ * The localtime(t) entry returns a pointer to an array
+ * containing
+ * seconds (0-59)
+ * minutes (0-59)
+ * hours (0-23)
+ * day of month (1-31)
+ * month (0-11)
+ * year-1970
+ * weekday (0-6, Sun is 0)
+ * day of the year
+ * daylight savings flag
+ *
+ * The routine corrects for daylight saving
+ * time and will work in any time zone provided
+ * "timezone" is adjusted to the difference between
+ * Greenwich and local standard time (measured in seconds).
+ * In places like Michigan "daylight" must
+ * be initialized to 0 to prevent the conversion
+ * to daylight time.
+ *
+ * "nixonflg,", if set to 1, will
+ * cause daylight savings time all year around
+ * independently of "daylight".
+ *
+ * The routine does not work
+ * in Saudi Arabia which runs on Solar time.
+ *
+ * asctime(tvec))
+ * where tvec is produced by localtime
+ * returns a ptr to a character string
+ * that has the ascii time in the form
+ * Thu Jan 01 00:00:00 1970n0\b\b\\
+ * 01234567890123456789012345
+ * 0 1 2
+ *
+ * ctime(t) just calls localtime, then asctime.
+ */
+char cbuf[26];
+int dmsize[12]
+{
+ 31,
+ 28,
+ 31,
+ 30,
+ 31,
+ 30,
+ 31,
+ 31,
+ 30,
+ 31,
+ 30,
+ 31
+};
+
+int timezone 5*60*60;
+int tzname[]
+{
+ "EST",
+ "EDT",
+};
+int daylight 1; /* Allow daylight conversion */
+int nixonflg 0; /* Daylight time all year around */
+
+#define SEC 0
+#define MIN 1
+#define HOUR 2
+#define MDAY 3
+#define MON 4
+#define YEAR 5
+#define WDAY 6
+#define YDAY 7
+#define ISDAY 8
+
+ctime(at)
+int *at;
+{
+ return(asctime(localtime(at)));
+}
+
+localtime(tim)
+int tim[];
+{
+ register int *t, *ct, dayno;
+ int daylbegin, daylend;
+ int copyt[2];
+
+ t = copyt;
+ t[0] = tim[0];
+ t[1] = tim[1];
+ dpadd(t, -timezone);
+ ct = gmtime(t);
+ dayno = ct[YDAY];
+ if (nixonflg && (ct[YEAR]>74 || ct[YEAR]==74 && (dayno > 5 ||
+ dayno==5 && ct[HOUR]>=2))) {
+ daylight =| 1;
+ daylbegin = -1;
+ daylend = 367;
+ } else {
+ daylbegin = sunday(ct, 119); /* last Sun in Apr */
+ daylend = sunday(ct, 303); /* last Sun in Oct */
+ }
+ if (daylight &&
+ (dayno>daylbegin || (dayno==daylbegin && ct[HOUR]>=2)) &&
+ (dayno<daylend || (dayno==daylend && ct[HOUR]<1))) {
+ dpadd(t, 1*60*60);
+ ct = gmtime(t);
+ ct[ISDAY]++;
+ }
+ return(ct);
+}
+
+sunday(at, ad)
+int *at;
+{
+ register int *t, d;
+
+ t = at;
+ d = ad;
+ d = ad + dysize(t[YEAR]) - 365;
+ return(d - (d - t[YDAY] + t[WDAY] + 700) % 7);
+}
+
+gmtime(tim)
+int tim[];
+{
+ register int d0, d1;
+ register *tp;
+ static xtime[9];
+ extern int ldivr;
+
+ /*
+ * break initial number into
+ * multiples of 8 hours.
+ * (28800 = 60*60*8)
+ */
+
+ d0 = ldiv(tim[0], tim[1], 28800);
+ d1 = ldivr;
+ tp = &xtime[0];
+
+ /*
+ * generate hours:minutes:seconds
+ */
+
+ *tp++ = d1%60;
+ d1 =/ 60;
+ *tp++ = d1%60;
+ d1 =/ 60;
+ d1 =+ (d0%3)*8;
+ d0 =/ 3;
+ *tp++ = d1;
+
+ /*
+ * d0 is the day number.
+ * generate day of the week.
+ */
+
+ xtime[WDAY] = (d0+4)%7;
+
+ /*
+ * year number
+ */
+ for(d1=70; d0 >= dysize(d1); d1++)
+ d0 =- dysize(d1);
+ xtime[YEAR] = d1;
+ xtime[YDAY] = d0;
+
+ /*
+ * generate month
+ */
+
+ if (dysize(d1)==366)
+ dmsize[1] = 29;
+ for(d1=0; d0 >= dmsize[d1]; d1++)
+ d0 =- dmsize[d1];
+ dmsize[1] = 28;
+ *tp++ = d0+1;
+ *tp++ = d1;
+ xtime[ISDAY] = 0;
+ return(xtime);
+}
+
+asctime(t)
+int *t;
+{
+ register char *cp, *ncp;
+ register int *tp;
+
+ cp = cbuf;
+ for (ncp = "Day Mon 00 00:00:00 1900\n"; *cp++ = *ncp++;);
+ ncp = &"SunMonTueWedThuFriSat"[3*t[6]];
+ cp = cbuf;
+ *cp++ = *ncp++;
+ *cp++ = *ncp++;
+ *cp++ = *ncp++;
+ cp++;
+ tp = &t[4];
+ ncp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[(*tp)*3];
+ *cp++ = *ncp++;
+ *cp++ = *ncp++;
+ *cp++ = *ncp++;
+ cp = numb(cp, *--tp);
+ cp = numb(cp, *--tp+100);
+ cp = numb(cp, *--tp+100);
+ cp = numb(cp, *--tp+100);
+ cp =+ 2;
+ cp = numb(cp, t[YEAR]);
+ return(cbuf);
+}
+
+dysize(y)
+{
+ if((y%4) == 0)
+ return(366);
+ return(365);
+}
+
+numb(acp, n)
+{
+ register char *cp;
+
+ cp = acp;
+ cp++;
+ if (n>=10)
+ *cp++ = (n/10)%10 + '0';
+ else
+ *cp++ = ' ';
+ *cp++ = n%10 + '0';
+ return(cp);
+}
projects / unix-history / commitdiff