glibc/time/Versions

libc {
  GLIBC_2.0 {
    # global variables
    __daylight; __timezone; __tzname;

    # functions with special/multiple interfaces
    __adjtimex;

    # functions used in other libraries
    __gmtime_r; __gettimeofday;

    # variables in normal name space
    daylight; timezone; tzname;

    # a*
    adjtime; adjtimex; asctime; asctime_r;

    # c*
    clock; ctime; ctime_r;

    # d*
    difftime; dysize;

    # f*
    ftime;

    # g*
    getitimer; gettimeofday; gmtime; gmtime_r;

    # l*
    localtime; localtime_r;

    # m*
    mktime;

    # s*
    setitimer; settimeofday; stime; strftime; strptime;

    # t*
    time; timegm; timelocal; tzset;
  }
  GLIBC_2.1 {
    # variables in normal name space
    getdate_err;

    # g*
    getdate; getdate_r;
  }
  GLIBC_2.2 {
    # w*
    wcsftime;

    # c*; actually in librt in version 2.2, moved to libc in 2.17
    clock_getres; clock_gettime; clock_settime; clock_getcpuclockid;
    clock_nanosleep;
  }
  GLIBC_2.3 {
    # these internal names are used by libstdc++
    __strftime_l; __wcsftime_l;

    # s*
    strftime_l;
    # w*
    wcsftime_l;
  }
  GLIBC_2.3.2 {
    strptime_l;
  }
  GLIBC_2.16 {
    timespec_get;
  }
  GLIBC_2.17 {
    # c*
    clock_getres; clock_gettime; clock_settime; clock_getcpuclockid;
    clock_nanosleep;
  }
  GLIBC_PRIVATE {
    # same as clock_gettime; used in other libraries
    __clock_gettime;
    __clock_gettime64;
  }
}