1 files changed, 86 insertions, 0 deletions
diff --git a/REORG.TODO/time/offtime.c b/REORG.TODO/time/offtime.c
new file mode 100644
index 0000000000..75a28fed84
--- /dev/null
+++ b/REORG.TODO/time/offtime.c
@@ -0,0 +1,86 @@
+/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <time.h>
+
+#define	SECS_PER_HOUR	(60 * 60)
+#define	SECS_PER_DAY	(SECS_PER_HOUR * 24)
+
+/* Compute the `struct tm' representation of *T,
+   offset OFFSET seconds east of UTC,
+   and store year, yday, mon, mday, wday, hour, min, sec into *TP.
+   Return nonzero if successful.  */
+int
+__offtime (const time_t *t, long int offset, struct tm *tp)
+{
+  time_t days, rem, y;
+  const unsigned short int *ip;
+
+  days = *t / SECS_PER_DAY;
+  rem = *t % SECS_PER_DAY;
+  rem += offset;
+  while (rem < 0)
+    {
+      rem += SECS_PER_DAY;
+      --days;
+    }
+  while (rem >= SECS_PER_DAY)
+    {
+      rem -= SECS_PER_DAY;
+      ++days;
+    }
+  tp->tm_hour = rem / SECS_PER_HOUR;
+  rem %= SECS_PER_HOUR;
+  tp->tm_min = rem / 60;
+  tp->tm_sec = rem % 60;
+  /* January 1, 1970 was a Thursday.  */
+  tp->tm_wday = (4 + days) % 7;
+  if (tp->tm_wday < 0)
+    tp->tm_wday += 7;
+  y = 1970;
+
+#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
+#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
+
+  while (days < 0 || days >= (__isleap (y) ? 366 : 365))
+    {
+      /* Guess a corrected year, assuming 365 days per year.  */
+      time_t yg = y + days / 365 - (days % 365 < 0);
+
+      /* Adjust DAYS and Y to match the guessed year.  */
+      days -= ((yg - y) * 365
+	       + LEAPS_THRU_END_OF (yg - 1)
+	       - LEAPS_THRU_END_OF (y - 1));
+      y = yg;
+    }
+  tp->tm_year = y - 1900;
+  if (tp->tm_year != y - 1900)
+    {
+      /* The year cannot be represented due to overflow.  */
+      __set_errno (EOVERFLOW);
+      return 0;
+    }
+  tp->tm_yday = days;
+  ip = __mon_yday[__isleap(y)];
+  for (y = 11; days < (long int) ip[y]; --y)
+    continue;
+  days -= ip[y];
+  tp->tm_mon = y;
+  tp->tm_mday = days + 1;
+  return 1;
+}