diff --git a/ChangeLog b/ChangeLog
index 7a20eb3..c1fb3e5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2016-04-10  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Fix integer overflow when adjusting posixrules
+	[BZ #19738]
+	This bug can occur on hosts with 32-bit time_t when reading tz files
+	generated by tz 2014c or later.  Problem reported by Aurelien
+	Jarno in: http://mm.icann.org/pipermail/tz/2016-March/023321.html
+	* include/intprops.h: New file, copied verbatim from Gnulib.
+	This newer version has an LGPLv2.1+ notice and a single year range.
+	* time/tzfile.c: Include "intprops.h".
+	(__tzfile_default): Check for time_t overflow when parsing
+	TZ='PST+8PDT' when the initial transition is at or near the
+	minimum time_t value.
+
 2016-04-09  Nick Alcock  <nick.alcock@oracle.com>
 
 	* elf/rtld-Rules (rtld-compile-command.c): Add $(rtld-CFLAGS).
diff --git a/include/intprops.h b/include/intprops.h
new file mode 100644
index 0000000..27fc9f9
--- /dev/null
+++ b/include/intprops.h
@@ -0,0 +1,429 @@
+/* intprops.h -- properties of integer types
+
+   Copyright (C) 2001-2016 Free Software Foundation, Inc.
+
+   This program 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.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Paul Eggert.  */
+
+#ifndef _GL_INTPROPS_H
+#define _GL_INTPROPS_H
+
+#include <limits.h>
+
+/* Return a value with the common real type of E and V and the value of V.  */
+#define _GL_INT_CONVERT(e, v) (0 * (e) + (v))
+
+/* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see
+   <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00406.html>.  */
+#define _GL_INT_NEGATE_CONVERT(e, v) (0 * (e) - (v))
+
+/* The extra casts in the following macros work around compiler bugs,
+   e.g., in Cray C 5.0.3.0.  */
+
+/* True if the arithmetic type T is an integer type.  bool counts as
+   an integer.  */
+#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
+
+/* True if negative values of the signed integer type T use two's
+   complement, ones' complement, or signed magnitude representation,
+   respectively.  Much GNU code assumes two's complement, but some
+   people like to be portable to all possible C hosts.  */
+#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
+#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
+#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
+
+/* True if the signed integer expression E uses two's complement.  */
+#define _GL_INT_TWOS_COMPLEMENT(e) (~ _GL_INT_CONVERT (e, 0) == -1)
+
+/* True if the real type T is signed.  */
+#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+
+/* Return 1 if the real expression E, after promotion, has a
+   signed or floating type.  */
+#define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0)
+
+
+/* Minimum and maximum values for integer types and expressions.  These
+   macros have undefined behavior if T is signed and has padding bits.
+   If this is a problem for you, please let us know how to fix it for
+   your host.  */
+
+/* The maximum and minimum values for the integer type T.  */
+#define TYPE_MINIMUM(t)                                                 \
+  ((t) (! TYPE_SIGNED (t)                                               \
+        ? (t) 0                                                         \
+        : TYPE_SIGNED_MAGNITUDE (t)                                     \
+        ? ~ (t) 0                                                       \
+        : ~ TYPE_MAXIMUM (t)))
+#define TYPE_MAXIMUM(t)                                                 \
+  ((t) (! TYPE_SIGNED (t)                                               \
+        ? (t) -1                                                        \
+        : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
+
+/* The maximum and minimum values for the type of the expression E,
+   after integer promotion.  E should not have side effects.  */
+#define _GL_INT_MINIMUM(e)                                              \
+  (EXPR_SIGNED (e)                                                      \
+   ? - _GL_INT_TWOS_COMPLEMENT (e) - _GL_SIGNED_INT_MAXIMUM (e)         \
+   : _GL_INT_CONVERT (e, 0))
+#define _GL_INT_MAXIMUM(e)                                              \
+  (EXPR_SIGNED (e)                                                      \
+   ? _GL_SIGNED_INT_MAXIMUM (e)                                         \
+   : _GL_INT_NEGATE_CONVERT (e, 1))
+#define _GL_SIGNED_INT_MAXIMUM(e)                                       \
+  (((_GL_INT_CONVERT (e, 1) << (sizeof ((e) + 0) * CHAR_BIT - 2)) - 1) * 2 + 1)
+
+
+/* Return 1 if the __typeof__ keyword works.  This could be done by
+   'configure', but for now it's easier to do it by hand.  */
+#if (2 <= __GNUC__ || defined __IBM__TYPEOF__ \
+     || (0x5110 <= __SUNPRO_C && !__STDC__))
+# define _GL_HAVE___TYPEOF__ 1
+#else
+# define _GL_HAVE___TYPEOF__ 0
+#endif
+
+/* Return 1 if the integer type or expression T might be signed.  Return 0
+   if it is definitely unsigned.  This macro does not evaluate its argument,
+   and expands to an integer constant expression.  */
+#if _GL_HAVE___TYPEOF__
+# define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t))
+#else
+# define _GL_SIGNED_TYPE_OR_EXPR(t) 1
+#endif
+
+/* Bound on length of the string representing an unsigned integer
+   value representable in B bits.  log10 (2.0) < 146/485.  The
+   smallest value of B where this bound is not tight is 2621.  */
+#define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485)
+
+/* Bound on length of the string representing an integer type or expression T.
+   Subtract 1 for the sign bit if T is signed, and then add 1 more for
+   a minus sign if needed.
+
+   Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is
+   signed, this macro may overestimate the true bound by one byte when
+   applied to unsigned types of size 2, 4, 16, ... bytes.  */
+#define INT_STRLEN_BOUND(t)                                     \
+  (INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT                 \
+                          - _GL_SIGNED_TYPE_OR_EXPR (t))        \
+   + _GL_SIGNED_TYPE_OR_EXPR (t))
+
+/* Bound on buffer size needed to represent an integer type or expression T,
+   including the terminating null.  */
+#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
+
+
+/* Range overflow checks.
+
+   The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C
+   operators might not yield numerically correct answers due to
+   arithmetic overflow.  They do not rely on undefined or
+   implementation-defined behavior.  Their implementations are simple
+   and straightforward, but they are a bit harder to use than the
+   INT_<op>_OVERFLOW macros described below.
+
+   Example usage:
+
+     long int i = ...;
+     long int j = ...;
+     if (INT_MULTIPLY_RANGE_OVERFLOW (i, j, LONG_MIN, LONG_MAX))
+       printf ("multiply would overflow");
+     else
+       printf ("product is %ld", i * j);
+
+   Restrictions on *_RANGE_OVERFLOW macros:
+
+   These macros do not check for all possible numerical problems or
+   undefined or unspecified behavior: they do not check for division
+   by zero, for bad shift counts, or for shifting negative numbers.
+
+   These macros may evaluate their arguments zero or multiple times,
+   so the arguments should not have side effects.  The arithmetic
+   arguments (including the MIN and MAX arguments) must be of the same
+   integer type after the usual arithmetic conversions, and the type
+   must have minimum value MIN and maximum MAX.  Unsigned types should
+   use a zero MIN of the proper type.
+
+   These macros are tuned for constant MIN and MAX.  For commutative
+   operations such as A + B, they are also tuned for constant B.  */
+
+/* Return 1 if A + B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  */
+#define INT_ADD_RANGE_OVERFLOW(a, b, min, max)          \
+  ((b) < 0                                              \
+   ? (a) < (min) - (b)                                  \
+   : (max) - (b) < (a))
+
+/* Return 1 if A - B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  */
+#define INT_SUBTRACT_RANGE_OVERFLOW(a, b, min, max)     \
+  ((b) < 0                                              \
+   ? (max) + (b) < (a)                                  \
+   : (a) < (min) + (b))
+
+/* Return 1 if - A would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  */
+#define INT_NEGATE_RANGE_OVERFLOW(a, min, max)          \
+  ((min) < 0                                            \
+   ? (a) < - (max)                                      \
+   : 0 < (a))
+
+/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  Avoid && and || as they tickle
+   bugs in Sun C 5.11 2010/08/13 and other compilers; see
+   <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00401.html>.  */
+#define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max)     \
+  ((b) < 0                                              \
+   ? ((a) < 0                                           \
+      ? (a) < (max) / (b)                               \
+      : (b) == -1                                       \
+      ? 0                                               \
+      : (min) / (b) < (a))                              \
+   : (b) == 0                                           \
+   ? 0                                                  \
+   : ((a) < 0                                           \
+      ? (a) < (min) / (b)                               \
+      : (max) / (b) < (a)))
+
+/* Return 1 if A / B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  Do not check for division by zero.  */
+#define INT_DIVIDE_RANGE_OVERFLOW(a, b, min, max)       \
+  ((min) < 0 && (b) == -1 && (a) < - (max))
+
+/* Return 1 if A % B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  Do not check for division by zero.
+   Mathematically, % should never overflow, but on x86-like hosts
+   INT_MIN % -1 traps, and the C standard permits this, so treat this
+   as an overflow too.  */
+#define INT_REMAINDER_RANGE_OVERFLOW(a, b, min, max)    \
+  INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max)
+
+/* Return 1 if A << B would overflow in [MIN,MAX] arithmetic.
+   See above for restrictions.  Here, MIN and MAX are for A only, and B need
+   not be of the same type as the other arguments.  The C standard says that
+   behavior is undefined for shifts unless 0 <= B < wordwidth, and that when
+   A is negative then A << B has undefined behavior and A >> B has
+   implementation-defined behavior, but do not check these other
+   restrictions.  */
+#define INT_LEFT_SHIFT_RANGE_OVERFLOW(a, b, min, max)   \
+  ((a) < 0                                              \
+   ? (a) < (min) >> (b)                                 \
+   : (max) >> (b) < (a))
+
+
+/* The _GL*_OVERFLOW macros have the same restrictions as the
+   *_RANGE_OVERFLOW macros, except that they do not assume that operands
+   (e.g., A and B) have the same type as MIN and MAX.  Instead, they assume
+   that the result (e.g., A + B) has that type.  */
+#define _GL_ADD_OVERFLOW(a, b, min, max)                                \
+  ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max)                  \
+   : (a) < 0 ? (b) <= (a) + (b)                                         \
+   : (b) < 0 ? (a) <= (a) + (b)                                         \
+   : (a) + (b) < (b))
+#define _GL_SUBTRACT_OVERFLOW(a, b, min, max)                           \
+  ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max)             \
+   : (a) < 0 ? 1                                                        \
+   : (b) < 0 ? (a) - (b) <= (a)                                         \
+   : (a) < (b))
+#define _GL_MULTIPLY_OVERFLOW(a, b, min, max)                           \
+  (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a))))       \
+   || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max))
+#define _GL_DIVIDE_OVERFLOW(a, b, min, max)                             \
+  ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max)  \
+   : (a) < 0 ? (b) <= (a) + (b) - 1                                     \
+   : (b) < 0 && (a) + (b) <= (a))
+#define _GL_REMAINDER_OVERFLOW(a, b, min, max)                          \
+  ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max)  \
+   : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b)                     \
+   : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max))
+
+/* Return a nonzero value if A is a mathematical multiple of B, where
+   A is unsigned, B is negative, and MAX is the maximum value of A's
+   type.  A's type must be the same as (A % B)'s type.  Normally (A %
+   -B == 0) suffices, but things get tricky if -B would overflow.  */
+#define _GL_UNSIGNED_NEG_MULTIPLE(a, b, max)                            \
+  (((b) < -_GL_SIGNED_INT_MAXIMUM (b)                                   \
+    ? (_GL_SIGNED_INT_MAXIMUM (b) == (max)                              \
+       ? (a)                                                            \
+       : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1))   \
+    : (a) % - (b))                                                      \
+   == 0)
+
+/* Check for integer overflow, and report low order bits of answer.
+
+   The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators
+   might not yield numerically correct answers due to arithmetic overflow.
+   The INT_<op>_WRAPV macros also store the low-order bits of the answer.
+   These macros work correctly on all known practical hosts, and do not rely
+   on undefined behavior due to signed arithmetic overflow.
+
+   Example usage, assuming A and B are long int:
+
+     if (INT_MULTIPLY_OVERFLOW (a, b))
+       printf ("result would overflow\n");
+     else
+       printf ("result is %ld (no overflow)\n", a * b);
+
+   Example usage with WRAPV flavor:
+
+     long int result;
+     bool overflow = INT_MULTIPLY_WRAPV (a, b, &result);
+     printf ("result is %ld (%s)\n", result,
+             overflow ? "after overflow" : "no overflow");
+
+   Restrictions on these macros:
+
+   These macros do not check for all possible numerical problems or
+   undefined or unspecified behavior: they do not check for division
+   by zero, for bad shift counts, or for shifting negative numbers.
+
+   These macros may evaluate their arguments zero or multiple times, so the
+   arguments should not have side effects.
+
+   The WRAPV macros are not constant expressions.  They support only
+   +, binary -, and *.  The result type must be signed.
+
+   These macros are tuned for their last argument being a constant.
+
+   Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
+   A % B, and A << B would overflow, respectively.  */
+
+#define INT_ADD_OVERFLOW(a, b) \
+  _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW)
+#define INT_SUBTRACT_OVERFLOW(a, b) \
+  _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW)
+#define INT_NEGATE_OVERFLOW(a) \
+  INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+#define INT_MULTIPLY_OVERFLOW(a, b) \
+  _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW)
+#define INT_DIVIDE_OVERFLOW(a, b) \
+  _GL_BINARY_OP_OVERFLOW (a, b, _GL_DIVIDE_OVERFLOW)
+#define INT_REMAINDER_OVERFLOW(a, b) \
+  _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW)
+#define INT_LEFT_SHIFT_OVERFLOW(a, b) \
+  INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, \
+                                 _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+
+/* Return 1 if the expression A <op> B would overflow,
+   where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test,
+   assuming MIN and MAX are the minimum and maximum for the result type.
+   Arguments should be free of side effects.  */
+#define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow)        \
+  op_result_overflow (a, b,                                     \
+                      _GL_INT_MINIMUM (0 * (b) + (a)),          \
+                      _GL_INT_MAXIMUM (0 * (b) + (a)))
+
+/* Compute A + B, A - B, A * B, respectively, storing the result into *R.
+   Return 1 if the result overflows.  See above for restrictions.  */
+#define INT_ADD_WRAPV(a, b, r) \
+  _GL_INT_OP_WRAPV (a, b, r, +, __builtin_add_overflow, INT_ADD_OVERFLOW)
+#define INT_SUBTRACT_WRAPV(a, b, r) \
+  _GL_INT_OP_WRAPV (a, b, r, -, __builtin_sub_overflow, INT_SUBTRACT_OVERFLOW)
+#define INT_MULTIPLY_WRAPV(a, b, r) \
+  _GL_INT_OP_WRAPV (a, b, r, *, __builtin_mul_overflow, INT_MULTIPLY_OVERFLOW)
+
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
+/* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390.  See:
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193
+   https://llvm.org/bugs/show_bug.cgi?id=25390
+   For now, assume all versions of GCC-like compilers generate bogus
+   warnings for _Generic.  This matters only for older compilers that
+   lack __builtin_add_overflow.  */
+#if __GNUC__
+# define _GL__GENERIC_BOGUS 1
+#else
+# define _GL__GENERIC_BOGUS 0
+#endif
+
+/* Store A <op> B into *R, where OP specifies the operation.
+   BUILTIN is the builtin operation, and OVERFLOW the overflow predicate.
+   See above for restrictions.  */
+#if 5 <= __GNUC__ || __has_builtin (__builtin_add_overflow)
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) builtin (a, b, r)
+#elif 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+   (_Generic \
+    (*(r), \
+     signed char: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
+                        signed char, SCHAR_MIN, SCHAR_MAX), \
+     short int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
+                        short int, SHRT_MIN, SHRT_MAX), \
+     int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                        int, INT_MIN, INT_MAX), \
+     long int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                        long int, LONG_MIN, LONG_MAX), \
+     long long int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+                        long long int, LLONG_MIN, LLONG_MAX)))
+#else
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+   (sizeof *(r) == sizeof (signed char) \
+    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
+                       signed char, SCHAR_MIN, SCHAR_MAX) \
+    : sizeof *(r) == sizeof (short int) \
+    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
+                       short int, SHRT_MIN, SHRT_MAX) \
+    : sizeof *(r) == sizeof (int) \
+    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                       int, INT_MIN, INT_MAX) \
+    : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow))
+# ifdef LLONG_MAX
+#  define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
+    (sizeof *(r) == sizeof (long int) \
+     ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                        long int, LONG_MIN, LONG_MAX) \
+     : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+                        long long int, LLONG_MIN, LLONG_MAX))
+# else
+#  define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
+    _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                     long int, LONG_MIN, LONG_MAX))
+# endif
+#endif
+
+/* Store the low-order bits of A <op> B into *R, where the operation
+   is given by OP.  Use the unsigned type UT for calculation to avoid
+   overflow problems.  *R's type is T, with extremal values TMIN and
+   TMAX.  T must be a signed integer type.  */
+#define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \
+  (sizeof ((a) op (b)) < sizeof (t) \
+   ? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \
+   : _GL_INT_OP_CALC1 (a, b, r, op, overflow, ut, t, tmin, tmax))
+#define _GL_INT_OP_CALC1(a, b, r, op, overflow, ut, t, tmin, tmax) \
+  ((overflow (a, b) \
+    || (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \
+    || (tmax) < ((a) op (b))) \
+   ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 1) \
+   : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 0))
+
+/* Return A <op> B, where the operation is given by OP.  Use the
+   unsigned type UT for calculation to avoid overflow problems.
+   Convert the result to type T without overflow by subtracting TMIN
+   from large values before converting, and adding it afterwards.
+   Compilers can optimize all the operations except OP.  */
+#define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t, tmin, tmax) \
+  (((ut) (a) op (ut) (b)) <= (tmax) \
+   ? (t) ((ut) (a) op (ut) (b)) \
+   : ((t) (((ut) (a) op (ut) (b)) - (tmin)) + (tmin)))
+
+#endif /* _GL_INTPROPS_H */
diff --git a/time/tzfile.c b/time/tzfile.c
index 9049878..f988d39 100644
--- a/time/tzfile.c
+++ b/time/tzfile.c
@@ -65,6 +65,7 @@ static char *tzspec;
 
 #include <endian.h>
 #include <byteswap.h>
+#include <intprops.h>
 
 /* Decode the four bytes at PTR as a signed integer in network byte order.  */
 static inline int
@@ -586,20 +587,26 @@ __tzfile_default (const char *std, const char *dst,
 	 the flavor of its original type.  */
       type_idxs[i] = trans_type->isdst;
 
-      if (trans_type->isgmt)
-	/* The transition time is in GMT.  No correction to apply.  */ ;
-      else if (isdst && !trans_type->isstd)
-	/* The type says this transition is in "local wall clock time", and
-	   wall clock time as of the previous transition was DST.  Correct
-	   for the difference between the rule's DST offset and the user's
-	   DST offset.  */
-	transitions[i] += dstoff - rule_dstoff;
-      else
-	/* This transition is in "local wall clock time", and wall clock
-	   time as of this iteration is non-DST.  Correct for the
-	   difference between the rule's standard offset and the user's
-	   standard offset.  */
-	transitions[i] += stdoff - rule_stdoff;
+      if (! trans_type->isgmt)
+	{
+	  long int correction;
+	  if (isdst && !trans_type->isstd)
+	    /* The type says this transition is in "local wall clock time", and
+	       wall clock time as of the previous transition was DST.  Correct
+	       for the difference between the rule's DST offset and the user's
+	       DST offset.  */
+	    correction = dstoff - rule_dstoff;
+	  else
+	    /* This transition is in "local wall clock time", and wall clock
+	       time as of this iteration is non-DST.  Correct for the
+	       difference between the rule's standard offset and the user's
+	       standard offset.  */
+	    correction = stdoff - rule_stdoff;
+	  if (INT_ADD_WRAPV (correction, transitions[i], &transitions[i]))
+	    transitions[i] = (correction < 0
+			      ? TYPE_MINIMUM (time_t)
+			      : TYPE_MAXIMUM (time_t));
+	}
 
       /* The DST state of "local wall clock time" for the next iteration is
 	 as specified by this transition.  */
