diff --git a/conform/data/threads.h-data b/conform/data/threads.h-data
index 406e497726..e938e0512c 100644
--- a/conform/data/threads.h-data
+++ b/conform/data/threads.h-data
@@ -34,6 +34,7 @@ function void thrd_yield (void)
 function int mtx_init (mtx_t*, int)
 function int mtx_lock (mtx_t*)
 function int mtx_timedlock (mtx_t*, const struct timespec*)
+function int mtx_timedlock_base (mtx_t*, int, const struct timespec*)
 function int mtx_trylock (mtx_t*)
 function int mtx_unlock (mtx_t*)
 function void mtx_destroy (mtx_t*)
@@ -45,6 +46,7 @@ function int cnd_signal (cnd_t*)
 function int cnd_broadcast (cnd_t*)
 function int cnd_wait (cnd_t*, mtx_t*)
 function int cnd_timedwait (cnd_t*, mtx_t*, const struct timespec*)
+function int cnd_timedwait_base (cnd_t*, mtx_t*, int, const struct timespec*)
 function void cnd_destroy (cnd_t*)
 
 function int tss_create (tss_t*, tss_dtor_t)
diff --git a/htl/Versions b/htl/Versions
index 70fa44631a..804005bfb9 100644
--- a/htl/Versions
+++ b/htl/Versions
@@ -170,6 +170,11 @@ libpthread {
     sem_clockwait;
   }
 
+  GLIBC_2.38 {
+    cnd_timedwait_base;
+    mtx_timedlock_base;
+  }
+
   GLIBC_PRIVATE {
     __pthread_initialize_minimal;
 
diff --git a/nptl/Versions b/nptl/Versions
index 3221de89d1..d44ab2b12d 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -525,6 +525,11 @@ libpthread {
   GLIBC_2.31 {
     __libpthread_version_placeholder;
   }
+
+  GLIBC_2.38 {
+    cnd_timedwait_base;
+    mtx_timedlock_base;
+  }
 }
 
 ld {
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index 32cf4eb119..a4a9d1b2cc 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -40,11 +40,13 @@ $(libpthread-routines-var) += \
   cnd_init \
   cnd_signal \
   cnd_timedwait \
+  cnd_timedwait_base \
   cnd_wait \
   mtx_destroy \
   mtx_init \
   mtx_lock \
   mtx_timedlock \
+  mtx_timedlock_base \
   mtx_trylock \
   mtx_unlock \
   pthread_atfork_compat \
diff --git a/sysdeps/pthread/cnd_timedwait_base.c b/sysdeps/pthread/cnd_timedwait_base.c
new file mode 100644
index 0000000000..e9be66ca0e
--- /dev/null
+++ b/sysdeps/pthread/cnd_timedwait_base.c
@@ -0,0 +1,29 @@
+/* C11 threads conditional timed wait implementation.
+   Copyright (C) 2018-2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include "thrd_priv.h"
+
+int
+cnd_timedwait_base (cnd_t *restrict cond, mtx_t *restrict mutex, int time_base,
+                    const struct timespec *restrict time_point)
+{
+  int err_code = __pthread_cond_clockwait ((pthread_cond_t *) cond,
+                                           (pthread_mutex_t *) mutex,
+                                           time_base, time_point);
+  return thrd_err_map (err_code);
+}
diff --git a/sysdeps/pthread/mtx_timedlock_base.c b/sysdeps/pthread/mtx_timedlock_base.c
new file mode 100644
index 0000000000..9aecf84440
--- /dev/null
+++ b/sysdeps/pthread/mtx_timedlock_base.c
@@ -0,0 +1,28 @@
+/* C11 threads mutex timed lock implementation.
+   Copyright (C) 2018-2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include "thrd_priv.h"
+
+int
+mtx_timedlock_base (mtx_t *restrict mutex, int time_base,
+                    const struct timespec *restrict time_point)
+{
+  int err_code = __pthread_mutex_clocklock ((pthread_mutex_t *) mutex,
+                                            time_base, time_point);
+  return thrd_err_map (err_code);
+}
diff --git a/sysdeps/pthread/threads.h b/sysdeps/pthread/threads.h
index d88d7a3ddd..4f61ad9236 100644
--- a/sysdeps/pthread/threads.h
+++ b/sysdeps/pthread/threads.h
@@ -146,14 +146,22 @@ extern int mtx_lock (mtx_t *__mutex);
 #ifndef __USE_TIME_BITS64
 extern int mtx_timedlock (mtx_t *__restrict __mutex,
 			  const struct timespec *__restrict __time_point);
+extern int mtx_timedlock_base (mtx_t *__restrict __mutex, int time_base,
+                               const struct timespec *__restrict __time_point);
 #else
 # ifdef __REDIRECT
 extern int __REDIRECT (mtx_timedlock, (mtx_t *__restrict __mutex,
                                        const struct timespec *__restrict
                                        __time_point),
                        __mtx_timedlock64);
+extern int __REDIRECT (mtx_timedlock_base, (mtx_t *__restrict __mutex,
+                                            int time_base,
+                                            const struct timespec *__restrict
+                                            __time_point),
+                       __mtx_timedlock_base64);
 # else
 #  define mtx_timedlock __mtx_timedlock64
+#  define mtx_timedlock_base __mtx_timedlock_base64
 # endif
 #endif
 
@@ -198,6 +206,9 @@ extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex);
 extern int cnd_timedwait (cnd_t *__restrict __cond,
 			  mtx_t *__restrict __mutex,
 			  const struct timespec *__restrict __time_point);
+extern int cnd_timedwait_base (cnd_t *__restrict __cond,
+                               mtx_t *__restrict __mutex, int time_base,
+                               const struct timespec *__restrict __time_point);
 #else
 # ifdef __REDIRECT
 extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond,
@@ -205,8 +216,15 @@ extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond,
                                        const struct timespec *__restrict
                                        __time_point),
                        __cnd_timedwait64);
+extern int __REDIRECT (cnd_timedwait_base, (cnd_t *__restrict __cond,
+                                            mtx_t *__restrict __mutex,
+                                            int time_base,
+                                            const struct timespec *__restrict
+                                            __time_point),
+                       __cnd_timedwait_base64);
 # else
 #  define cnd_timedwait __cnd_timedwait64
+#  define cnd_timedwait_base __cnd_timedwait_base64
 # endif
 #endif
 
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index bc59bce42f..73ce24bea6 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -319,6 +319,12 @@ libc {
   GLIBC_2.37 {
 %ifdef TIME64_NON_DEFAULT
     __ppoll64_chk;
+%endif
+  }
+  GLIBC_2.38 {
+%ifdef TIME64_NON_DEFAULT
+    __cnd_timedwait_base64;
+    __mtx_timedlock_base64;
 %endif
   }
   GLIBC_PRIVATE {
diff --git a/sysdeps/unix/sysv/linux/cnd_timedwait_base.c b/sysdeps/unix/sysv/linux/cnd_timedwait_base.c
new file mode 100644
index 0000000000..2e851a7aec
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/cnd_timedwait_base.c
@@ -0,0 +1,53 @@
+/* C11 threads conditional timed wait implementation - Linux variant.
+   Copyright (C) 2020-2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <shlib-compat.h>
+#include "thrd_priv.h"
+
+int
+__cnd_timedwait_base64 (cnd_t *restrict cond, mtx_t *restrict mutex,
+                        int time_base,
+                        const struct __timespec64 *restrict time_point)
+{
+  int err_code = __pthread_cond_clockwait64 ((pthread_cond_t *) cond,
+                                             (pthread_mutex_t *) mutex,
+                                             time_base, time_point);
+  return thrd_err_map (err_code);
+}
+
+#if __TIMESIZE == 64
+strong_alias (__cnd_timedwait_base64, ___cnd_timedwait_base)
+#else
+libc_hidden_def (__cnd_timedwait_base64)
+
+int
+___cnd_timedwait_base (cnd_t *restrict cond, mtx_t *restrict mutex,
+                       int time_base,
+                       const struct timespec *restrict time_point)
+{
+  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*time_point);
+
+  return __cnd_timedwait_base64 (cond, mutex, time_base, &ts64);
+}
+#endif /* __TIMESIZE == 64 */
+versioned_symbol (libc, ___cnd_timedwait_base, cnd_timedwait_base, GLIBC_2_34);
+
+#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_28, GLIBC_2_34)
+compat_symbol (libpthread, ___cnd_timedwait_base, cnd_timedwait_base, GLIBC_2_28);
+#endif
diff --git a/sysdeps/unix/sysv/linux/mtx_timedlock_base.c b/sysdeps/unix/sysv/linux/mtx_timedlock_base.c
new file mode 100644
index 0000000000..046fb86091
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mtx_timedlock_base.c
@@ -0,0 +1,50 @@
+/* C11 threads mutex timed lock implementation - Linux variant.
+   Copyright (C) 2020-2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <shlib-compat.h>
+#include "thrd_priv.h"
+
+int
+__mtx_timedlock_base64 (mtx_t *restrict mutex, int time_base,
+                        const struct __timespec64 *restrict time_point)
+{
+  int err_code = __pthread_mutex_clocklock64 ((pthread_mutex_t *) mutex,
+                                              time_base, time_point);
+  return thrd_err_map (err_code);
+}
+
+#if __TIMESIZE == 64
+strong_alias (__mtx_timedlock_base64, ___mtx_timedlock_base)
+#else
+libc_hidden_def (__mtx_timedlock_base64)
+
+int
+___mtx_timedlock_base (mtx_t *restrict mutex, int time_base,
+                       const struct timespec *restrict time_point)
+{
+  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*time_point);
+
+  return __mtx_timedlock_base64 (mutex, time_base, &ts64);
+}
+#endif /* __TIMESIZE == 64 */
+versioned_symbol (libc, ___mtx_timedlock_base, mtx_timedlock_base, GLIBC_2_34);
+
+#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_28, GLIBC_2_34)
+compat_symbol (libpthread, ___mtx_timedlock_base, mtx_timedlock_base, GLIBC_2_28);
+#endif
diff --git a/sysdeps/unix/sysv/linux/thrd_priv.h b/sysdeps/unix/sysv/linux/thrd_priv.h
index af23a10a07..8ea9ced507 100644
--- a/sysdeps/unix/sysv/linux/thrd_priv.h
+++ b/sysdeps/unix/sysv/linux/thrd_priv.h
@@ -20,15 +20,25 @@
 
 #if __TIMESIZE == 64
 # define __cnd_timedwait64 __cnd_timedwait
+# define __cnd_timedwait_base64 __cnd_timedwait_base
 # define __mtx_timedlock64 __mtx_timedlock
+# define __mtx_timedlock_base64 __mtx_timedlock_base
 # define __thrd_sleep64 __thrd_sleep
 #else
 extern int __cnd_timedwait64 (cnd_t *restrict cond, mtx_t *restrict mutex,
                               const struct __timespec64 *restrict time_point);
 libc_hidden_proto (__cnd_timedwait64)
+extern int __cnd_timedwait_base64 (cnd_t *restrict cond, mtx_t *restrict mutex,
+                                   int time_base,
+                                   const struct __timespec64 *restrict time_point);
+libc_hidden_proto (__cnd_timedwait_base64)
 extern int __mtx_timedlock64 (mtx_t *restrict mutex,
                               const struct __timespec64 *restrict time_point);
 libc_hidden_proto (__mtx_timedlock64)
+extern int __mtx_timedlock_base64 (mtx_t *restrict mutex, int time_base,
+                                   const struct __timespec64 *restrict
+                                   time_point);
+libc_hidden_proto (__mtx_timedlock_base64)
 extern int __thrd_sleep64 (const struct __timespec64 *time_point,
                            struct __timespec64 *remaining);
 libc_hidden_proto (__thrd_sleep64)
