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+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// -----------------------------------------------------------------------------
+// File: time.h
+// -----------------------------------------------------------------------------
+//
+// This header file defines abstractions for computing with absolute points
+// in time, durations of time, and formatting and parsing time within a given
+// time zone. The following abstractions are defined:
+//
+//  * `absl::Time` defines an absolute, specific instance in time
+//  * `absl::Duration` defines a signed, fixed-length span of time
+//  * `absl::TimeZone` defines geopolitical time zone regions (as collected
+//     within the IANA Time Zone database (https://www.iana.org/time-zones)).
+//
+// Example:
+//
+//   absl::TimeZone nyc;
+//
+//   // LoadTimeZone may fail so it's always better to check for success.
+//   if (!absl::LoadTimeZone("America/New_York", &nyc)) {
+//      // handle error case
+//   }
+//
+//   // My flight leaves NYC on Jan 2, 2017 at 03:04:05
+//   absl::Time takeoff = absl::FromDateTime(2017, 1, 2, 3, 4, 5, nyc);
+//   absl::Duration flight_duration = absl::Hours(21) + absl::Minutes(35);
+//   absl::Time landing = takeoff + flight_duration;
+//
+//   absl::TimeZone syd;
+//   if (!absl::LoadTimeZone("Australia/Sydney", &syd)) {
+//      // handle error case
+//   }
+//   std::string s = absl::FormatTime(
+//       "My flight will land in Sydney on %Y-%m-%d at %H:%M:%S",
+//       landing, syd);
+//
+#ifndef ABSL_TIME_TIME_H_
+#define ABSL_TIME_TIME_H_
+
+#if !defined(_WIN32)
+#include <sys/time.h>
+#else
+#include <winsock2.h>
+#endif
+#include <chrono>  // NOLINT(build/c++11)
+#include <cstdint>
+#include <ctime>
+#include <ostream>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+#include "absl/base/port.h"  // Needed for string vs std::string
+#include "cctz/time_zone.h"
+
+namespace absl {
+
+class Duration;      // Defined below
+class Time;          // Defined below
+class TimeZone;      // Defined below
+
+namespace time_internal {
+int64_t IDivDuration(bool satq, Duration num, Duration den, Duration* rem);
+constexpr Time FromUnixDuration(Duration d);
+constexpr Duration ToUnixDuration(Time t);
+constexpr int64_t GetRepHi(Duration d);
+constexpr uint32_t GetRepLo(Duration d);
+constexpr Duration MakeDuration(int64_t hi, uint32_t lo);
+constexpr Duration MakeDuration(int64_t hi, int64_t lo);
+constexpr int64_t kTicksPerNanosecond = 4;
+constexpr int64_t kTicksPerSecond = 1000 * 1000 * 1000 * kTicksPerNanosecond;
+template <typename T>
+using IsFloatingPoint =
+    typename std::enable_if<std::is_floating_point<T>::value, int>::type;
+}  // namespace time_internal
+
+// Duration
+//
+// The `absl::Duration` class represents a signed, fixed-length span of time.
+// A `Duration` is generated using a unit-specific factory function, or is
+// the result of subtracting one `absl::Time` from another. Durations behave
+// like unit-safe integers and they support all the natural integer-like
+// arithmetic operations. Arithmetic overflows and saturates at +/- infinity.
+// `Duration` should be passed by value rather than const reference.
+//
+// Factory functions `Nanoseconds()`, `Microseconds()`, `Milliseconds()`,
+// `Seconds()`, `Minutes()`, `Hours()` and `InfiniteDuration()` allow for
+// creation of constexpr `Duration` values
+//
+// Examples:
+//
+//   constexpr absl::Duration ten_ns = absl::Nanoseconds(10);
+//   constexpr absl::Duration min = absl::Minutes(1);
+//   constexpr absl::Duration hour = absl::Hours(1);
+//   absl::Duration dur = 60 * min;  // dur == hour
+//   absl::Duration half_sec = absl::Milliseconds(500);
+//   absl::Duration quarter_sec = 0.25 * absl::Seconds(1);
+//
+// `Duration` values can be easily converted to an integral number of units
+// using the division operator.
+//
+// Example:
+//
+//   constexpr absl::Duration dur = absl::Milliseconds(1500);
+//   int64_t ns = dur / absl::Nanoseconds(1);   // ns == 1500000000
+//   int64_t ms = dur / absl::Milliseconds(1);  // ms == 1500
+//   int64_t sec = dur / absl::Seconds(1);    // sec == 1 (subseconds truncated)
+//   int64_t min = dur / absl::Minutes(1);    // min == 0
+//
+// See the `IDivDuration()` and `FDivDuration()` functions below for details on
+// how to access the fractional parts of the quotient.
+//
+// Alternatively, conversions can be performed using helpers such as
+// `ToInt64Microseconds()` and `ToDoubleSeconds()`.
+class Duration {
+ public:
+  // Value semantics.
+  constexpr Duration() : rep_hi_(0), rep_lo_(0) {}  // zero-length duration
+
+  // Compound assignment operators.
+  Duration& operator+=(Duration d);
+  Duration& operator-=(Duration d);
+  Duration& operator*=(int64_t r);
+  Duration& operator*=(double r);
+  Duration& operator/=(int64_t r);
+  Duration& operator/=(double r);
+  Duration& operator%=(Duration rhs);
+
+  // Overloads that forward to either the int64_t or double overloads above.
+  template <typename T>
+  Duration& operator*=(T r) {
+    int64_t x = r;
+    return *this *= x;
+  }
+  template <typename T>
+  Duration& operator/=(T r) {
+    int64_t x = r;
+    return *this /= x;
+  }
+  Duration& operator*=(float r) { return *this *= static_cast<double>(r); }
+  Duration& operator/=(float r) { return *this /= static_cast<double>(r); }
+
+ private:
+  friend constexpr int64_t time_internal::GetRepHi(Duration d);
+  friend constexpr uint32_t time_internal::GetRepLo(Duration d);
+  friend constexpr Duration time_internal::MakeDuration(int64_t hi,
+                                                        uint32_t lo);
+  constexpr Duration(int64_t hi, uint32_t lo) : rep_hi_(hi), rep_lo_(lo) {}
+  int64_t rep_hi_;
+  uint32_t rep_lo_;
+};
+
+// Relational Operators
+constexpr bool operator<(Duration lhs, Duration rhs);
+constexpr bool operator>(Duration lhs, Duration rhs) { return rhs < lhs; }
+constexpr bool operator>=(Duration lhs, Duration rhs) { return !(lhs < rhs); }
+constexpr bool operator<=(Duration lhs, Duration rhs) { return !(rhs < lhs); }
+constexpr bool operator==(Duration lhs, Duration rhs);
+constexpr bool operator!=(Duration lhs, Duration rhs) { return !(lhs == rhs); }
+
+// Additive Operators
+constexpr Duration operator-(Duration d);
+inline Duration operator+(Duration lhs, Duration rhs) { return lhs += rhs; }
+inline Duration operator-(Duration lhs, Duration rhs) { return lhs -= rhs; }
+
+// Multiplicative Operators
+template <typename T>
+inline Duration operator*(Duration lhs, T rhs) {
+  return lhs *= rhs;
+}
+template <typename T>
+inline Duration operator*(T lhs, Duration rhs) {
+  return rhs *= lhs;
+}
+template <typename T>
+inline Duration operator/(Duration lhs, T rhs) {
+  return lhs /= rhs;
+}
+inline int64_t operator/(Duration lhs, Duration rhs) {
+  return time_internal::IDivDuration(true, lhs, rhs,
+                                     &lhs);  // trunc towards zero
+}
+inline Duration operator%(Duration lhs, Duration rhs) { return lhs %= rhs; }
+
+// IDivDuration()
+//
+// Divides a numerator `Duration` by a denominator `Duration`, returning the
+// quotient and remainder. The remainder always has the same sign as the
+// numerator. The returned quotient and remainder respect the identity:
+//
+//   numerator = denominator * quotient + remainder
+//
+// Returned quotients are capped to the range of `int64_t`, with the difference
+// spilling into the remainder to uphold the above identity. This means that the
+// remainder returned could differ from the remainder returned by
+// `Duration::operator%` for huge quotients.
+//
+// See also the notes on `InfiniteDuration()` below regarding the behavior of
+// division involving zero and infinite durations.
+//
+// Example:
+//
+//   constexpr absl::Duration a =
+//       absl::Seconds(std::numeric_limits<int64_t>::max());  // big
+//   constexpr absl::Duration b = absl::Nanoseconds(1);       // small
+//
+//   absl::Duration rem = a % b;
+//   // rem == absl::ZeroDuration()
+//
+//   // Here, q would overflow int64_t, so rem accounts for the difference.
+//   int64_t q = absl::IDivDuration(a, b, &rem);
+//   // q == std::numeric_limits<int64_t>::max(), rem == a - b * q
+inline int64_t IDivDuration(Duration num, Duration den, Duration* rem) {
+  return time_internal::IDivDuration(true, num, den,
+                                     rem);  // trunc towards zero
+}
+
+// FDivDuration()
+//
+// Divides a `Duration` numerator into a fractional number of units of a
+// `Duration` denominator.
+//
+// See also the notes on `InfiniteDuration()` below regarding the behavior of
+// division involving zero and infinite durations.
+//
+// Example:
+//
+//   double d = absl::FDivDuration(absl::Milliseconds(1500), absl::Seconds(1));
+//   // d == 1.5
+double FDivDuration(Duration num, Duration den);
+
+// ZeroDuration()
+//
+// Returns a zero-length duration. This function behaves just like the default
+// constructor, but the name helps make the semantics clear at call sites.
+constexpr Duration ZeroDuration() { return Duration(); }
+
+// AbsDuration()
+//
+// Returns the absolute value of a duration.
+inline Duration AbsDuration(Duration d) {
+  return (d < ZeroDuration()) ? -d : d;
+}
+
+// Trunc()
+//
+// Truncates a duration (toward zero) to a multiple of a non-zero unit.
+//
+// Example:
+//
+//   absl::Duration d = absl::Nanoseconds(123456789);
+//   absl::Duration a = absl::Trunc(d, absl::Microseconds(1));  // 123456us
+Duration Trunc(Duration d, Duration unit);
+
+// Floor()
+//
+// Floors a duration using the passed duration unit to its largest value not
+// greater than the duration.
+//
+// Example:
+//
+//   absl::Duration d = absl::Nanoseconds(123456789);
+//   absl::Duration b = absl::Floor(d, absl::Microseconds(1));  // 123456us
+Duration Floor(Duration d, Duration unit);
+
+// Ceil()
+//
+// Returns the ceiling of a duration using the passed duration unit to its
+// smallest value not less than the duration.
+//
+// Example:
+//
+//   absl::Duration d = absl::Nanoseconds(123456789);
+//   absl::Duration c = absl::Ceil(d, absl::Microseconds(1));   // 123457us
+Duration Ceil(Duration d, Duration unit);
+
+// Nanoseconds()
+// Microseconds()
+// Milliseconds()
+// Seconds()
+// Minutes
+// Hours()
+//
+// Factory functions for constructing `Duration` values from an integral number
+// of the unit indicated by the factory function's name.
+//
+// Note: no "Days()" factory function exists because "a day" is ambiguous. Civil
+// days are not always 24 hours long, and a 24-hour duration often does not
+// correspond with a civil day. If a 24-hour duration is needed, use
+// `absl::Hours(24)`.
+//
+//
+// Example:
+//
+//   absl::Duration a = absl::Seconds(60);
+//   absl::Duration b = absl::Minutes(1);  // b == a
+constexpr Duration Nanoseconds(int64_t n);
+constexpr Duration Microseconds(int64_t n);
+constexpr Duration Milliseconds(int64_t n);
+constexpr Duration Seconds(int64_t n);
+constexpr Duration Minutes(int64_t n);
+constexpr Duration Hours(int64_t n);
+
+// Factory overloads for constructing `Duration` values from a floating-point
+// number of the unit indicated by the factory function's name. These functions
+// exist for convenience, but they are not as efficient as the integral
+// factories, which should be preferred.
+//
+// Example:
+//   auto a = absl::Seconds(1.5);        // OK
+//   auto b = absl::Milliseconds(1500);  // BETTER
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Nanoseconds(T n) {
+  return n * Nanoseconds(1);
+}
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Microseconds(T n) {
+  return n * Microseconds(1);
+}
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Milliseconds(T n) {
+  return n * Milliseconds(1);
+}
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Seconds(T n) {
+  return n * Seconds(1);
+}
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Minutes(T n) {
+  return n * Minutes(1);
+}
+template <typename T, time_internal::IsFloatingPoint<T> = 0>
+Duration Hours(T n) {
+  return n * Hours(1);
+}
+
+// ToInt64Nanoseconds()
+// ToInt64Microseconds()
+// ToInt64Milliseconds()
+// ToInt64Seconds()
+// ToInt64Minutes()
+// ToInt64Hours()
+//
+// Helper functions that convert a Duration to an integral count of the
+// indicated unit. These functions are shorthand for the `IDivDuration()`
+// function above; see its documentation for details about overflow, etc.
+//
+// Example:
+//
+//   absl::Duration d = absl::Milliseconds(1500);
+//   int64_t isec = ToInt64Seconds(d);    // isec == 1
+int64_t ToInt64Nanoseconds(Duration d);
+int64_t ToInt64Microseconds(Duration d);
+int64_t ToInt64Milliseconds(Duration d);
+int64_t ToInt64Seconds(Duration d);
+int64_t ToInt64Minutes(Duration d);
+int64_t ToInt64Hours(Duration d);
+
+// ToDoubleNanoSeconds()
+// ToDoubleMicroseconds()
+// ToDoubleMilliseconds()
+// ToDoubleSeconds()
+// ToDoubleMinutes()
+// ToDoubleHours
+//
+// Helper functions that convert a Duration to a floating point count of the
+// indicated unit. These functions are shorthand for the `FDivDuration()`
+// function above; see its documentation for details about overflow, etc.
+//
+// Example:
+//
+//   absl::Duration d = absl::Milliseconds(1500);
+//   double dsec = ToDoubleSeconds(d);  // dsec == 1.5
+double ToDoubleNanoseconds(Duration d);
+double ToDoubleMicroseconds(Duration d);
+double ToDoubleMilliseconds(Duration d);
+double ToDoubleSeconds(Duration d);
+double ToDoubleMinutes(Duration d);
+double ToDoubleHours(Duration d);
+
+// InfiniteDuration()
+//
+// Returns an infinite `Duration`.  To get a `Duration` representing negative
+// infinity, use `-InfiniteDuration()`.
+//
+// Duration arithmetic overflows to +/- infinity and saturates. In general,
+// arithmetic with `Duration` infinities is similar to IEEE 754 infinities
+// except where IEEE 754 NaN would be involved, in which case +/-
+// `InfiniteDuration()` is used in place of a "nan" Duration.
+//
+// Examples:
+//
+//   constexpr absl::Duration inf = absl::InfiniteDuration();
+//   const absl::Duration d = ... any finite duration ...
+//
+//   inf == inf + inf
+//   inf == inf + d
+//   inf == inf - inf
+//   -inf == d - inf
+//
+//   inf == d * 1e100
+//   inf == inf / 2
+//   0 == d / inf
+//   INT64_MAX == inf / d
+//
+//   // Division by zero returns infinity, or INT64_MIN/MAX where appropriate.
+//   inf == d / 0
+//   INT64_MAX == d / absl::ZeroDuration()
+//
+// The examples involving the `/` operator above also apply to `IDivDuration()`
+// and `FDivDuration()`.
+constexpr Duration InfiniteDuration();
+
+// FormatDuration()
+//
+// Returns a std::string representing the duration in the form "72h3m0.5s".
+// Returns "inf" or "-inf" for +/- `InfiniteDuration()`.
+std::string FormatDuration(Duration d);
+
+// Output stream operator.
+inline std::ostream& operator<<(std::ostream& os, Duration d) {
+  return os << FormatDuration(d);
+}
+
+// ParseDuration()
+//
+// Parses a duration std::string consisting of a possibly signed sequence
+// of decimal numbers, each with an optional fractional part and a
+// unit suffix.  The valid suffixes are "ns", "us" "ms", "s", "m",
+// and "h".  Simple examples include "300ms", "-1.5h", and "2h45m".
+// Parses "inf" and "-inf" as +/- `InfiniteDuration()`.
+bool ParseDuration(const std::string& dur_string, Duration* d);
+
+// Flag Support
+// TODO(b/63899288) copybara strip once dependencies are removed.
+
+// ParseFlag()
+//
+bool ParseFlag(const std::string& text, Duration* dst, std::string* error);
+
+// UnparseFlag()
+//
+std::string UnparseFlag(Duration d);
+
+// Time
+//
+// An `absl::Time` represents a specific instant in time. Arithmetic operators
+// are provided for naturally expressing time calculations. Instances are
+// created using `absl::Now()` and the `absl::From*()` factory functions that
+// accept the gamut of other time representations. Formatting and parsing
+// functions are provided for conversion to and from strings.  `absl::Time`
+// should be passed by value rather than const reference.
+//
+// `absl::Time` assumes there are 60 seconds in a minute, which means the
+// underlying time scales must be "smeared" to eliminate leap seconds.
+// POSIX, for example, legislates that a `time_t` value of `536457599` shall
+// correspond to "1986-12-31 23:59:59 +0000".
+//
+//
+// Even though `absl::Time` supports a wide range of timestamps, exercise
+// caution when using values in the distant past. `absl::Time` uses the
+// Proleptic Gregorian calendar, which extends the Gregorian calendar backward
+// to dates before its introduction in 1582.
+// See https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar
+// for more information. Use the ICU calendar classes to convert a date in
+// some other calendar (http://userguide.icu-project.org/datetime/calendar).
+//
+// Similarly, standardized time zones are a reasonably recent innovation, with
+// the Greenwich prime meridian being established in 1884. The TZ database
+// itself does not profess accurate offsets for timestamps prior to 1970. The
+// breakdown of future timestamps is subject to the whim of regional
+// governments.
+//
+// The `absl::Time` class represents an instant in time as a count of clock
+// ticks of some granularity (resolution) from some starting point (epoch).
+//
+//
+// `absl::Time` uses a resolution that is high enough to avoid loss in
+// precision, and a range that is wide enough to avoid overflow, when
+// converting between tick counts in most Google time scales (i.e., precision
+// of at least one nanosecond, and range +/-100 billion years).  Conversions
+// between the time scales are performed by truncating (towards negative
+// infinity) to the nearest representable point.
+//
+// Examples:
+//
+//   absl::Time t1 = ...;
+//   absl::Time t2 = t1 + absl::Minutes(2);
+//   absl::Duration d = t2 - t1;  // == absl::Minutes(2)
+//   absl::Time::Breakdown bd = t1.In(absl::LocalTimeZone());
+//
+class Time {
+ public:
+  // Value semantics.
+
+  // Returns the Unix epoch.  However, those reading your code may not know
+  // or expect the Unix epoch as the default value, so make your code more
+  // readable by explicitly initializing all instances before use.
+  //
+  // Example:
+  //   absl::Time t = absl::UnixEpoch();
+  //   absl::Time t = absl::Now();
+  //   absl::Time t = absl::TimeFromTimeval(tv);
+  //   absl::Time t = absl::InfinitePast();
+  constexpr Time() {}
+
+  // Assignment operators.
+  Time& operator+=(Duration d) { rep_ += d;  return *this; }
+  Time& operator-=(Duration d) { rep_ -= d;  return *this; }
+
+  // Time::Breakdown
+  //
+  // The calendar and wall-clock (aka "civil time") components of a
+  // `absl::Time` in a certain `absl::TimeZone`. This struct is not
+  // intended to represent an instant in time. So, rather than passing
+  // a `Time::Breakdown` to a function, pass an `absl::Time` and an
+  // `absl::TimeZone`.
+  struct Breakdown {
+    int64_t year;             // year (e.g., 2013)
+    int month;              // month of year [1:12]
+    int day;                // day of month [1:31]
+    int hour;               // hour of day [0:23]
+    int minute;             // minute of hour [0:59]
+    int second;             // second of minute [0:59]
+    Duration subsecond;     // [Seconds(0):Seconds(1)) if finite
+    int weekday;            // 1==Mon, ..., 7=Sun
+    int yearday;            // day of year [1:366]
+
+    // Note: The following fields exist for backward compatibility
+    // with older APIs.  Accessing these fields directly is a sign of
+    // imprudent logic in the calling code.  Modern time-related code
+    // should only access this data indirectly by way of FormatTime().
+    // These fields are undefined for InfiniteFuture() and InfinitePast().
+    int offset;             // seconds east of UTC
+    bool is_dst;            // is offset non-standard?
+    const char* zone_abbr;  // time-zone abbreviation (e.g., "PST")
+  };
+
+  // Time::In()
+  //
+  // Returns the breakdown of this instant in the given TimeZone.
+  Breakdown In(TimeZone tz) const;
+
+ private:
+  friend constexpr Time time_internal::FromUnixDuration(Duration d);
+  friend constexpr Duration time_internal::ToUnixDuration(Time t);
+  friend constexpr bool operator<(Time lhs, Time rhs);
+  friend constexpr bool operator==(Time lhs, Time rhs);
+  friend Duration operator-(Time lhs, Time rhs);
+  friend constexpr Time UniversalEpoch();
+  friend constexpr Time InfiniteFuture();
+  friend constexpr Time InfinitePast();
+  constexpr explicit Time(Duration rep) : rep_(rep) {}
+  Duration rep_;
+};
+
+// Relational Operators
+constexpr bool operator<(Time lhs, Time rhs) { return lhs.rep_ < rhs.rep_; }
+constexpr bool operator>(Time lhs, Time rhs) { return rhs < lhs; }
+constexpr bool operator>=(Time lhs, Time rhs) { return !(lhs < rhs); }
+constexpr bool operator<=(Time lhs, Time rhs) { return !(rhs < lhs); }
+constexpr bool operator==(Time lhs, Time rhs) { return lhs.rep_ == rhs.rep_; }
+constexpr bool operator!=(Time lhs, Time rhs) { return !(lhs == rhs); }
+
+// Additive Operators
+inline Time operator+(Time lhs, Duration rhs) { return lhs += rhs; }
+inline Time operator+(Duration lhs, Time rhs) { return rhs += lhs; }
+inline Time operator-(Time lhs, Duration rhs) { return lhs -= rhs; }
+inline Duration operator-(Time lhs, Time rhs) { return lhs.rep_ - rhs.rep_; }
+
+// UnixEpoch()
+//
+// Returns the `absl::Time` representing "1970-01-01 00:00:00.0 +0000".
+constexpr Time UnixEpoch() {
+  return Time();
+}
+
+// UniversalEpoch()
+//
+// Returns the `absl::Time` representing "0001-01-01 00:00:00.0 +0000", the
+// epoch of the ICU Universal Time Scale.
+constexpr Time UniversalEpoch() {
+  // 719162 is the number of days from 0001-01-01 to 1970-01-01,
+  // assuming the Gregorian calendar.
+  return Time(time_internal::MakeDuration(-24 * 719162 * int64_t{3600}, 0U));
+}
+
+// InfiniteFuture()
+//
+// Returns an `absl::Time` that is infinitely far in the future.
+constexpr Time InfiniteFuture() {
+  return Time(
+      time_internal::MakeDuration(std::numeric_limits<int64_t>::max(), ~0U));
+}
+
+// InfinitePast()
+//
+// Returns an `absl::Time` that is infinitely far in the past.
+constexpr Time InfinitePast() {
+  return Time(
+      time_internal::MakeDuration(std::numeric_limits<int64_t>::min(), ~0U));
+}
+
+// TimeConversion
+//
+// An `absl::TimeConversion` represents the conversion of year, month, day,
+// hour, minute, and second values (i.e., a civil time), in a particular
+// `absl::TimeZone`, to a time instant (an absolute time), as returned by
+// `absl::ConvertDateTime()`. (Subseconds must be handled separately.)
+//
+// It is possible, though, for a caller to try to convert values that
+// do not represent an actual or unique instant in time (due to a shift
+// in UTC offset in the `absl::TimeZone`, which results in a discontinuity in
+// the civil-time components). For example, a daylight-saving-time
+// transition skips or repeats civil times---in the United States, March
+// 13, 2011 02:15 never occurred, while November 6, 2011 01:15 occurred
+// twice---so requests for such times are not well-defined.
+//
+// To account for these possibilities, `absl::TimeConversion` is richer
+// than just a single `absl::Time`. When the civil time is skipped or
+// repeated, `absl::ConvertDateTime()` returns times calculated using the
+// pre-transition and post-transition UTC offsets, plus the transition
+// time itself.
+//
+// Examples:
+//
+//   absl::TimeZone lax;
+//   if (!absl::LoadTimeZone("America/Los_Angeles", &lax)) { ... }
+//
+//   // A unique civil time
+//   absl::TimeConversion jan01 =
+//       absl::ConvertDateTime(2011, 1, 1, 0, 0, 0, lax);
+//   // jan01.kind == TimeConversion::UNIQUE
+//   // jan01.pre    is 2011/01/01 00:00:00 -0800
+//   // jan01.trans  is 2011/01/01 00:00:00 -0800
+//   // jan01.post   is 2011/01/01 00:00:00 -0800
+//
+//   // A Spring DST transition, when there is a gap in civil time
+//   absl::TimeConversion mar13 =
+//       absl::ConvertDateTime(2011, 3, 13, 2, 15, 0, lax);
+//   // mar13.kind == TimeConversion::SKIPPED
+//   // mar13.pre   is 2011/03/13 03:15:00 -0700
+//   // mar13.trans is 2011/03/13 03:00:00 -0700
+//   // mar13.post  is 2011/03/13 01:15:00 -0800
+//
+//   // A Fall DST transition, when civil times are repeated
+//   absl::TimeConversion nov06 =
+//       absl::ConvertDateTime(2011, 11, 6, 1, 15, 0, lax);
+//   // nov06.kind == TimeConversion::REPEATED
+//   // nov06.pre   is 2011/11/06 01:15:00 -0700
+//   // nov06.trans is 2011/11/06 01:00:00 -0800
+//   // nov06.post  is 2011/11/06 01:15:00 -0800
+//
+// The input month, day, hour, minute, and second values can also be
+// outside of their valid ranges, in which case they will be "normalized"
+// during the conversion.
+//
+// Example:
+//
+//   // "October 32" normalizes to "November 1".
+//   absl::TimeZone tz = absl::LocalTimeZone();
+//   absl::TimeConversion tc =
+//       absl::ConvertDateTime(2013, 10, 32, 8, 30, 0, tz);
+//   // tc.kind == TimeConversion::UNIQUE && tc.normalized == true
+//   // tc.pre.In(tz).month == 11 && tc.pre.In(tz).day == 1
+struct TimeConversion {
+  Time pre;         // time calculated using the pre-transition offset
+  Time trans;       // when the civil-time discontinuity occurred
+  Time post;        // time calculated using the post-transition offset
+
+  enum Kind {
+    UNIQUE,         // the civil time was singular (pre == trans == post)
+    SKIPPED,        // the civil time did not exist
+    REPEATED,       // the civil time was ambiguous
+  };
+  Kind kind;
+
+  bool normalized;  // input values were outside their valid ranges
+};
+
+// ConvertDateTime()
+//
+// The full generality of a civil time to absl::Time conversion.
+TimeConversion ConvertDateTime(int64_t year, int mon, int day, int hour,
+                               int min, int sec, TimeZone tz);
+
+// FromDateTime()
+//
+// A convenience wrapper for `absl::ConvertDateTime()` that simply returns the
+// "pre" `absl::Time`.  That is, the unique result, or the instant that
+// is correct using the pre-transition offset (as if the transition
+// never happened). This is typically the answer that humans expected when
+// faced with non-unique times, such as near daylight-saving time transitions.
+//
+// Example:
+//
+//   absl::TimeZone seattle;
+//   if (!absl::LoadTimeZone("America/Los_Angeles", &seattle)) { ... }
+//   absl::Time t =  absl::FromDateTime(2017, 9, 26, 9, 30, 0, seattle);
+Time FromDateTime(int64_t year, int mon, int day, int hour, int min, int sec,
+                  TimeZone tz);
+
+// FromTM()
+//
+// Converts the `tm_year`, `tm_mon`, `tm_mday`, `tm_hour`, `tm_min`, and
+// `tm_sec` fields to an `absl::Time` using the given time zone. See ctime(3)
+// for a description of the expected values of the tm fields. IFF the indicated
+// time instant is not unique (see `absl::ConvertDateTime()` above), the
+// `tm_isdst` field is consulted to select the desired instant (`tm_isdst` > 0
+// means DST, `tm_isdst` == 0 means no DST, `tm_isdst` < 0 means use the default
+// like `absl::FromDateTime()`).
+Time FromTM(const struct tm& tm, TimeZone tz);
+
+// ToTM()
+//
+// Converts the given `absl::Time` to a struct tm using the given time zone.
+// See ctime(3) for a description of the values of the tm fields.
+struct tm ToTM(Time t, TimeZone tz);
+
+// FromUnixNanos()
+// FromUnixMicros()
+// FromUnixMillis()
+// FromUnixSeconds()
+// FromTimeT()
+// FromUDate()
+// FromUniversal()
+//
+// Creates an `absl::Time` from a variety of other representations.
+constexpr Time FromUnixNanos(int64_t ns);
+constexpr Time FromUnixMicros(int64_t us);
+constexpr Time FromUnixMillis(int64_t ms);
+constexpr Time FromUnixSeconds(int64_t s);
+constexpr Time FromTimeT(time_t t);
+Time FromUDate(double udate);
+Time FromUniversal(int64_t universal);
+
+// ToUnixNanos()
+// ToUnixMicros()
+// ToUnixMillis()
+// ToUnixSeconds()
+// ToTimeT()
+// ToUDate()
+// ToUniversal()
+//
+// Converts an `absl::Time` to a variety of other representations.  Note that
+// these operations round down toward negative infinity where necessary to
+// adjust to the resolution of the result type.  Beware of possible time_t
+// over/underflow in ToTime{T,val,spec}() on 32-bit platforms.
+int64_t ToUnixNanos(Time t);
+int64_t ToUnixMicros(Time t);
+int64_t ToUnixMillis(Time t);
+int64_t ToUnixSeconds(Time t);
+time_t ToTimeT(Time t);
+double ToUDate(Time t);
+int64_t ToUniversal(Time t);
+
+// DurationFromTimespec()
+// DurationFromTimeval()
+// ToTimespec()
+// ToTimeval()
+// TimeFromTimespec()
+// TimeFromTimeval()
+// ToTimespec()
+// ToTimeval()
+//
+// Some APIs use a timespec or a timeval as a Duration (e.g., nanosleep(2)
+// and select(2)), while others use them as a Time (e.g. clock_gettime(2)
+// and gettimeofday(2)), so conversion functions are provided for both cases.
+// The "to timespec/val" direction is easily handled via overloading, but
+// for "from timespec/val" the desired type is part of the function name.
+Duration DurationFromTimespec(timespec ts);
+Duration DurationFromTimeval(timeval tv);
+timespec ToTimespec(Duration d);
+timeval ToTimeval(Duration d);
+Time TimeFromTimespec(timespec ts);
+Time TimeFromTimeval(timeval tv);
+timespec ToTimespec(Time t);
+timeval ToTimeval(Time t);
+
+// RFC3339_full
+// RFC3339_sec
+//
+// FormatTime()/ParseTime() format specifiers for RFC3339 date/time strings,
+// with trailing zeros trimmed or with fractional seconds omitted altogether.
+//
+// Note that RFC3339_sec[] matches an ISO 8601 extended format for date
+// and time with UTC offset.
+extern const char RFC3339_full[];  // %Y-%m-%dT%H:%M:%E*S%Ez
+extern const char RFC3339_sec[];   // %Y-%m-%dT%H:%M:%S%Ez
+
+// RFC1123_full
+// RFC1123_no_wday
+//
+// FormatTime()/ParseTime() format specifiers for RFC1123 date/time strings.
+extern const char RFC1123_full[];  // %a, %d %b %E4Y %H:%M:%S %z
+extern const char RFC1123_no_wday[];   // %d %b %E4Y %H:%M:%S %z
+
+// FormatTime()
+//
+// Formats the given `absl::Time` in the `absl::TimeZone` according to the
+// provided format std::string. Uses strftime()-like formatting options, with
+// the following extensions:
+//
+//   - %Ez  - RFC3339-compatible numeric time zone (+hh:mm or -hh:mm)
+//   - %E#S - Seconds with # digits of fractional precision
+//   - %E*S - Seconds with full fractional precision (a literal '*')
+//   - %E#f - Fractional seconds with # digits of precision
+//   - %E*f - Fractional seconds with full precision (a literal '*')
+//   - %E4Y - Four-character years (-999 ... -001, 0000, 0001 ... 9999)
+//
+// Note that %E0S behaves like %S, and %E0f produces no characters.  In
+// contrast %E*f always produces at least one digit, which may be '0'.
+//
+// Note that %Y produces as many characters as it takes to fully render the
+// year.  A year outside of [-999:9999] when formatted with %E4Y will produce
+// more than four characters, just like %Y.
+//
+// We recommend that format strings include %Ez so that the result uniquely
+// identifies a time instant.
+//
+// Example:
+//
+//   absl::TimeZone lax;
+//   if (!absl::LoadTimeZone("America/Los_Angeles", &lax)) { ... }
+//   absl::Time t = absl::FromDateTime(2013, 1, 2, 3, 4, 5, lax);
+//
+//   std::string f = absl::FormatTime("%H:%M:%S", t, lax);  // "03:04:05"
+//   f = absl::FormatTime("%H:%M:%E3S", t, lax);  // "03:04:05.000"
+//
+// Note: If the given `absl::Time` is `absl::InfiniteFuture()`, the returned
+// std::string will be exactly "infinite-future". If the given `absl::Time` is
+// `absl::InfinitePast()`, the returned std::string will be exactly "infinite-past".
+// In both cases the given format std::string and `absl::TimeZone` are ignored.
+//
+std::string FormatTime(const std::string& format, Time t, TimeZone tz);
+
+// Convenience functions that format the given time using the RFC3339_full
+// format.  The first overload uses the provided TimeZone, while the second
+// uses LocalTimeZone().
+std::string FormatTime(Time t, TimeZone tz);
+std::string FormatTime(Time t);
+
+// Output stream operator.
+inline std::ostream& operator<<(std::ostream& os, Time t) {
+  return os << FormatTime(t);
+}
+
+// ParseTime()
+//
+// Parses an input std::string according to the provided format std::string and
+// returns the corresponding `absl::Time`. Uses strftime()-like formatting
+// options, with the same extensions as FormatTime(), but with the
+// exceptions that %E#S is interpreted as %E*S, and %E#f as %E*f.
+//
+// %Y consumes as many numeric characters as it can, so the matching data
+// should always be terminated with a non-numeric.  %E4Y always consumes
+// exactly four characters, including any sign.
+//
+// Unspecified fields are taken from the default date and time of ...
+//
+//   "1970-01-01 00:00:00.0 +0000"
+//
+// For example, parsing a std::string of "15:45" (%H:%M) will return a absl::Time
+// that represents "1970-01-01 15:45:00.0 +0000".  Note: Since ParseTime()
+// returns time instants, it makes the most sense to parse fully-specified
+// date/time strings that include a UTC offset (%z/%Ez), such as those
+// matching RFC3339_full above.
+//
+// Note also that `absl::ParseTime()` only heeds the fields year, month, day,
+// hour, minute, (fractional) second, and UTC offset.  Other fields, like
+// weekday (%a or %A), while parsed for syntactic validity, are ignored
+// in the conversion.
+//
+// Date and time fields that are out-of-range will be treated as errors
+// rather than normalizing them like `absl::FromDateTime()` does.  For example,
+// it is an error to parse the date "Oct 32, 2013" because 32 is out of range.
+//
+// A leap second of ":60" is normalized to ":00" of the following minute
+// with fractional seconds discarded.  The following table shows how the
+// given seconds and subseconds will be parsed:
+//
+//   "59.x" -> 59.x  // exact
+//   "60.x" -> 00.0  // normalized
+//   "00.x" -> 00.x  // exact
+//
+// Errors are indicated by returning false and assigning an error message
+// to the "err" out param if it is non-null.
+//
+// Note: If the input std::string is exactly "infinite-future", the returned
+// `absl::Time` will be `absl::InfiniteFuture()` and `true` will be returned.
+// If the input std::string is "infinite-past", the returned `absl::Time` will be
+// `absl::InfinitePast()` and `true` will be returned.
+//
+bool ParseTime(const std::string& format, const std::string& input,
+               Time* time, std::string* err);
+
+// Like ParseTime() above, but if the format std::string does not contain a UTC
+// offset specification (%z/%Ez) then the input is interpreted in the given
+// TimeZone.  This means that the input, by itself, does not identify a
+// unique instant.  Being time-zone dependent, it also admits the possibility
+// of ambiguity or non-existence, in which case the "pre" time (as defined
+// for ConvertDateTime()) is returned.  For these reasons we recommend that
+// all date/time strings include a UTC offset so they're context independent.
+bool ParseTime(const std::string& format, const std::string& input, TimeZone tz,
+               Time* time, std::string* err);
+
+// TODO(b/63899288) copybara strip once dependencies are removed.
+
+// ParseFlag()
+// UnparseFlag()
+//
+// Support for flag values of type Time. Time flags must be specified in a
+// format that matches absl::RFC3339_full. For example:
+//
+//   --start_time=2016-01-02T03:04:05.678+08:00
+//
+// Note: A UTC offset (or 'Z' indicating a zero-offset from UTC) is required.
+// If your application doesn't have a UTC offset to specify, perhaps you're
+// really specifying a Civil Time
+// Additionally, if you'd like to specify a time as a count of
+// seconds/milliseconds/etc from the Unix epoch, use a absl::Duration flag and
+// add that duration to absl::UnixEpoch() to get a absl::Time.
+bool ParseFlag(const std::string& text, Time* t, std::string* error);
+std::string UnparseFlag(Time t);
+
+// TimeZone
+//
+// The `absl::TimeZone` is an opaque, small, value-type class representing a
+// geo-political region within which particular rules are used for converting
+// between absolute and civil times (see https://git.io/v59Ly). `absl::TimeZone`
+// values are named using the TZ identifiers from the IANA Time Zone Database,
+// such as "America/Los_Angeles" or "Australia/Sydney". `absl::TimeZone` values
+// are created from factory functions such as `absl::LoadTimeZone()`. Note:
+// strings like "PST" and "EDT" are not valid TZ identifiers. Prefer to pass by
+// value rather than const reference.
+//
+// For more on the fundamental concepts of time zones, absolute times, and civil
+// times, see https://github.com/google/cctz#fundamental-concepts
+//
+// Examples:
+//
+//   absl::TimeZone utc = absl::UTCTimeZone();
+//   absl::TimeZone pst = absl::FixedTimeZone(-8 * 60 * 60);
+//   absl::TimeZone loc = absl::LocalTimeZone();
+//   absl::TimeZone lax;
+//   if (!absl::LoadTimeZone("America/Los_Angeles", &lax)) { ... }
+//
+// See also:
+// - https://github.com/google/cctz
+// - http://www.iana.org/time-zones
+// - http://en.wikipedia.org/wiki/Zoneinfo
+//   TimeZone backing data with your binary.
+class TimeZone {
+ public:
+  explicit TimeZone(cctz::time_zone tz) : cz_(tz) {}
+  TimeZone() = default;  // UTC, but prefer UTCTimeZone() to be explicit.
+  TimeZone(const TimeZone&) = default;
+  TimeZone& operator=(const TimeZone&) = default;
+
+  explicit operator cctz::time_zone() const { return cz_; }
+
+  std::string name() const { return cz_.name(); }
+
+ private:
+  friend bool operator==(TimeZone a, TimeZone b) { return a.cz_ == b.cz_; }
+  friend bool operator!=(TimeZone a, TimeZone b) { return a.cz_ != b.cz_; }
+  friend std::ostream& operator<<(std::ostream& os, TimeZone tz) {
+    return os << tz.name();
+  }
+
+  cctz::time_zone cz_;
+};
+
+// LoadTimeZone()
+//
+// Loads the named zone. May perform I/O on the initial load of the named
+// zone. If the name is invalid, or some other kind of error occurs, returns
+// `false` and `*tz` is set to the UTC time zone.
+inline bool LoadTimeZone(const std::string& name, TimeZone* tz) {
+  if (name == "localtime") {
+    *tz = TimeZone(cctz::local_time_zone());
+    return true;
+  }
+  cctz::time_zone cz;
+  const bool b = cctz::load_time_zone(name, &cz);
+  *tz = TimeZone(cz);
+  return b;
+}
+
+// FixedTimeZone()
+//
+// Returns a TimeZone that is a fixed offset (seconds east) from UTC.
+// Note: If the absolute value of the offset is greater than 24 hours
+// you'll get UTC (i.e., no offset) instead.
+inline TimeZone FixedTimeZone(int seconds) {
+  return TimeZone(cctz::fixed_time_zone(std::chrono::seconds(seconds)));
+}
+
+// UTCTimeZone()
+//
+// Convenience method returning the UTC time zone.
+inline TimeZone UTCTimeZone() { return TimeZone(cctz::utc_time_zone()); }
+
+// LocalTimeZone()
+//
+// Convenience method returning the local time zone, or UTC if there is
+// no configured local zone.  Warning: Be wary of using LocalTimeZone(),
+// and particularly so in a server process, as the zone configured for the
+// local machine should be irrelevant.  Prefer an explicit zone name.
+inline TimeZone LocalTimeZone() { return TimeZone(cctz::local_time_zone()); }
+
+// ============================================================================
+// Implementation Details Follow
+// ============================================================================
+
+namespace time_internal {
+
+// Creates a Duration with a given representation.
+// REQUIRES: hi,lo is a valid representation of a Duration as specified
+// in time/duration.cc.
+constexpr Duration MakeDuration(int64_t hi, uint32_t lo = 0) {
+  return Duration(hi, lo);
+}
+
+constexpr Duration MakeDuration(int64_t hi, int64_t lo) {
+  return time_internal::MakeDuration(hi, static_cast<uint32_t>(lo));
+}
+
+// Creates a normalized Duration from an almost-normalized (sec,ticks)
+// pair. sec may be positive or negative.  ticks must be in the range
+// -kTicksPerSecond < *ticks < kTicksPerSecond.  If ticks is negative it
+// will be normalized to a positive value in the resulting Duration.
+constexpr Duration MakeNormalizedDuration(int64_t sec, int64_t ticks) {
+  return (ticks < 0)
+             ? time_internal::MakeDuration(sec - 1, ticks + kTicksPerSecond)
+             : time_internal::MakeDuration(sec, ticks);
+}
+// Provide access to the Duration representation.
+constexpr int64_t GetRepHi(Duration d) { return d.rep_hi_; }
+constexpr uint32_t GetRepLo(Duration d) { return d.rep_lo_; }
+constexpr bool IsInfiniteDuration(Duration d) { return GetRepLo(d) == ~0U; }
+
+// Returns an infinite Duration with the opposite sign.
+// REQUIRES: IsInfiniteDuration(d)
+constexpr Duration OppositeInfinity(Duration d) {
+  return GetRepHi(d) < 0
+             ? MakeDuration(std::numeric_limits<int64_t>::max(), ~0U)
+             : MakeDuration(std::numeric_limits<int64_t>::min(), ~0U);
+}
+
+// Returns (-n)-1 (equivalently -(n+1)) without overflowing on any input value.
+constexpr int64_t NegateAndSubtractOne(int64_t n) {
+  return (n < 0) ? -(n + 1) : (-n) - 1;
+}
+
+// Map between a Time and a Duration since the Unix epoch.  Note that these
+// functions depend on the above mentioned choice of the Unix epoch for the
+// Time representation (and both need to be Time friends).  Without this
+// knowledge, we would need to add-in/subtract-out UnixEpoch() respectively.
+constexpr Time FromUnixDuration(Duration d) { return Time(d); }
+constexpr Duration ToUnixDuration(Time t) { return t.rep_; }
+}  // namespace time_internal
+
+constexpr bool operator<(Duration lhs, Duration rhs) {
+  return time_internal::GetRepHi(lhs) != time_internal::GetRepHi(rhs)
+             ? time_internal::GetRepHi(lhs) < time_internal::GetRepHi(rhs)
+             : time_internal::GetRepHi(lhs) == std::numeric_limits<int64_t>::min()
+                   ? time_internal::GetRepLo(lhs) + 1 <
+                         time_internal::GetRepLo(rhs) + 1
+                   : time_internal::GetRepLo(lhs) <
+                         time_internal::GetRepLo(rhs);
+}
+
+constexpr bool operator==(Duration lhs, Duration rhs) {
+  return time_internal::GetRepHi(lhs) == time_internal::GetRepHi(rhs) &&
+         time_internal::GetRepLo(lhs) == time_internal::GetRepLo(rhs);
+}
+
+constexpr Duration operator-(Duration d) {
+  // This is a little interesting because of the special cases.
+  //
+  // Infinities stay infinite, and just change direction.
+  //
+  // The maximum negative finite duration can't be negated (at least, not
+  // on a two's complement machine), so we return infinity for that case.
+  // Next we dispatch the case where rep_lo_ is zero, observing that it's
+  // safe to negate rep_hi_ in this case because it's not int64_t-min (or
+  // else we'd have handled it above, returning InfiniteDuration()).
+  //
+  // Finally we're in the case where rep_lo_ is non-zero, and we can borrow
+  // a second's worth of ticks and avoid overflow (as negating int64_t-min + 1
+  // is safe).
+  return time_internal::IsInfiniteDuration(d)
+             ? time_internal::OppositeInfinity(d)
+             : (time_internal::GetRepHi(d) ==
+                    std::numeric_limits<int64_t>::min() &&
+                time_internal::GetRepLo(d) == 0)
+                   ? InfiniteDuration()
+                   : (time_internal::GetRepLo(d) == 0)
+                         ? time_internal::MakeDuration(
+                               -time_internal::GetRepHi(d))
+                         : time_internal::MakeDuration(
+                               time_internal::NegateAndSubtractOne(
+                                   time_internal::GetRepHi(d)),
+                               time_internal::kTicksPerSecond -
+                                   time_internal::GetRepLo(d));
+}
+
+constexpr Duration Nanoseconds(int64_t n) {
+  return time_internal::MakeNormalizedDuration(
+      n / (1000 * 1000 * 1000),
+      n % (1000 * 1000 * 1000) * time_internal::kTicksPerNanosecond);
+}
+
+constexpr Duration Microseconds(int64_t n) {
+  return time_internal::MakeNormalizedDuration(
+      n / (1000 * 1000),
+      n % (1000 * 1000) * (1000 * time_internal::kTicksPerNanosecond));
+}
+
+constexpr Duration Milliseconds(int64_t n) {
+  return time_internal::MakeNormalizedDuration(
+      n / 1000, n % 1000 * (1000 * 1000 * time_internal::kTicksPerNanosecond));
+}
+
+constexpr Duration Seconds(int64_t n) { return time_internal::MakeDuration(n); }
+
+constexpr Duration Minutes(int64_t n) {
+  return (n <= std::numeric_limits<int64_t>::max() / 60 &&
+          n >= std::numeric_limits<int64_t>::min() / 60)
+             ? time_internal::MakeDuration(n * 60)
+             : n > 0 ? InfiniteDuration() : -InfiniteDuration();
+}
+
+constexpr Duration Hours(int64_t n) {
+  return (n <= std::numeric_limits<int64_t>::max() / 3600 &&
+          n >= std::numeric_limits<int64_t>::min() / 3600)
+             ? time_internal::MakeDuration(n * 3600)
+             : n > 0 ? InfiniteDuration() : -InfiniteDuration();
+}
+
+constexpr Duration InfiniteDuration() {
+  return time_internal::MakeDuration(std::numeric_limits<int64_t>::max(), ~0U);
+}
+
+constexpr Time FromUnixNanos(int64_t ns) {
+  return time_internal::FromUnixDuration(Nanoseconds(ns));
+}
+
+constexpr Time FromUnixMicros(int64_t us) {
+  return time_internal::FromUnixDuration(Microseconds(us));
+}
+
+constexpr Time FromUnixMillis(int64_t ms) {
+  return time_internal::FromUnixDuration(Milliseconds(ms));
+}
+
+constexpr Time FromUnixSeconds(int64_t s) {
+  return time_internal::FromUnixDuration(Seconds(s));
+}
+
+constexpr Time FromTimeT(time_t t) {
+  return time_internal::FromUnixDuration(Seconds(t));
+}
+
+}  // namespace absl
+
+#endif  // ABSL_TIME_TIME_H_