[gcc r13-8431] libstdc++: Update expiry times for leap seconds lists

[Jonathan Wakely]

https://gcc.gnu.org/g:1870ee44351f182e8782238e9a6732e842eebf1d

commit r13-8431-g1870ee44351f182e8782238e9a6732e842eebf1d
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Mar 1 20:55:10 2024 +0000

    libstdc++: Update expiry times for leap seconds lists
    
    The list in tzdb.cc isn't the only hardcoded list of leap seconds in the
    library, there's the one defined inline in <chrono> (to avoid loading
    the tzdb for the common case) and another in a testcase. This updates
    them to note that there are no new leap seconds in 2024 either, until at
    least 2024-12-28.
    
    libstdc++-v3/ChangeLog:
    
            * include/std/chrono (__get_leap_second_info): Update expiry
            time for hardcoded list of leap seconds.
            * testsuite/std/time/tzdb/leap_seconds.cc: Update comment.
    
    (cherry picked from commit ddd347fca0685804bf68d6c768282573f3ea6442)

Diff:
---
 libstdc++-v3/include/std/chrono                      | 2 +-
 libstdc++-v3/testsuite/std/time/tzdb/leap_seconds.cc | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono
index b2abf90cf71..edb782f6f10 100644
--- a/libstdc++-v3/include/std/chrono
+++ b/libstdc++-v3/include/std/chrono
@@ -3253,7 +3253,7 @@ namespace __detail
       };
       // The list above is known to be valid until (at least) this date
       // and only contains positive leap seconds.
-      const sys_seconds __expires(1703721600s); // 2023-12-28 00:00:00 UTC
+      const sys_seconds __expires(1735344000s); // 2024-12-28 00:00:00 UTC
 
 #if _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
       if (__ss > __expires)
diff --git a/libstdc++-v3/testsuite/std/time/tzdb/leap_seconds.cc b/libstdc++-v3/testsuite/std/time/tzdb/leap_seconds.cc
index d27038225c8..537fb0670ff 100644
--- a/libstdc++-v3/testsuite/std/time/tzdb/leap_seconds.cc
+++ b/libstdc++-v3/testsuite/std/time/tzdb/leap_seconds.cc
@@ -22,7 +22,7 @@ void
 test_load_leapseconds()
 {
   std::ofstream("leapseconds") << R"(
-# These are all the real leap seconds as of 2022:
+# These are all the real leap seconds as of 2024:
 Leap	1972	Jun	30	23:59:60	+	S
 Leap	1972	Dec	31	23:59:60	+	S
 Leap	1973	Dec	31	23:59:60	+	S