Why does Perl never fail to convert strings into numbers when numbers are required EXCEPT when passing parameters to timelocal() (from Time::Local)?

use Time::Local;


my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime()
+;


my $datetime = timelocal (0,0,0,$mday,$mon,$year);

print "$datetime $sec $min $hour $mday $mon $year\n";

$datetime = timelocal (0,0,0,12,11,106);

print "$datetime $sec $min $hour $mday $mon $year\n";

($sec, $min, $hour, $mday, $mon, $year) = (0,0,0,12,11,106);

$datetime = timelocal ($sec, $min, $hour, $mday, $mon, $year);

print "$datetime $sec $min $hour $mday $mon $year\n";

$myage = age ("1966/7/30");
print "my age in days: $myage\n";

sub age
{
    my $date = shift @_;
    my ($year,$mon,$mday) = split m%/%, $date;

#my failed attempt to coerce the type to be integer
    my ($iyear, $imon, $imday) = (0,0,0);
    $iyear += $year;
    $imon += $mon;
    $imday += $mday;
    
    $imon--; #shift range from 1-12 to 0-11
    $iyear -= 1900;
    my $modulus = 60*60*24; #number of seconds in a day.
    my $now = time();
    my $remainder = $now % $modulus;
    $now -= $remainder;
    $now /= $modulus; #number of days since the epoch
    my $datetime = timelocal(0,0,0,$imday,$imon,$iyear);
    $datetime /= $modulus;
    return $now - $datetime;
}

Output:
C:\CONVER~1>perl -w test3.pl
1165899600 47 35 12 12 11 106
1165899600 47 35 12 12 11 106
1165899600 0 0 0 12 11 106
Day too small - -1251 > -1
Sec too small - -1251 < 68400
Cannot handle date (0, 0, 0, 30, 6, 1966) at test3.pl line 40


I am using ActivePerl:
C:\CONVER~1>perl -V
Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=MSWin32, osvers=5.0, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    usethreads=define use5005threads=undef useithreads=define usemulti
+plicity=de
fine
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cl', ccflags ='-nologo -GF -W3 -MD -Zi -DNDEBUG -O1 -DWIN32 -D
+_CONSOLE -
DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DUSE_SITECUSTOMIZE -DPERL
+_IMPLICIT_
CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX',
    optimize='-MD -Zi -DNDEBUG -O1',
    cppflags='-DWIN32'
    ccversion='12.00.8804', gccversion='', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64
+', lseeksi
ze=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='link', ldflags ='-nologo -nodefaultlib -debug -opt:ref,icf  -l
+ibpath:"C:
\Perl\lib\CORE"  -machine:x86'
    libpth=\lib
    libs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib
+  comdlg32
.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib uui
+d.lib ws2_
32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib msvcrt.l
+ib
    perllibs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool
+.lib  comd
lg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib
+ uuid.lib
ws2_32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib msvc
+rt.lib
    libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl58.lib
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -debug -opt:
+ref,icf  -
libpath:"C:\Perl\lib\CORE"  -machine:x86'


Characteristics of this binary (from libperl):
  Compile-time options: MULTIPLICITY PERL_IMPLICIT_CONTEXT
                        PERL_IMPLICIT_SYS PERL_MALLOC_WRAP
                        PL_OP_SLAB_ALLOC USE_ITHREADS USE_LARGE_FILES
                        USE_PERLIO USE_SITECUSTOMIZE
  Locally applied patches:
        ActivePerl Build 819 [267479]
        Iin_load_module moved for compatibility with build 806
        PerlEx support in CGI::Carp
        Less verbose ExtUtils::Install and Pod::Find
        Patch for CAN-2005-0448 from Debian with modifications
        Rearrange @INC so that 'site' is searched before 'perl'
        Partly reverted 24733 to preserve binary compatibility
        28671 Define PERL_NO_DEV_RANDOM on Windows
        28376 Add error checks after execing PL_cshname or PL_sh_path
        28305 Pod::Html should not convert "foo" into ``foo''
        27736 Make perl_fini() run with Sun WorkShop compiler
        27619 Bug in Term::ReadKey being triggered by a bug in Term::R
+eadLine
        27549 Move DynaLoader.o into libperl.so
        27528 win32_pclose() error exit doesn't unlock mutex
        27527 win32_async_check() can loop indefinitely
        27515 ignore directories when searching @INC
        27359 Fix -d:Foo=bar syntax
        27210 Fix quote typo in c2ph
        27203 Allow compiling swigged C++ code
        27200 Make stat() on Windows handle trailing slashes correctly
        27194 Get perl_fini() running on HP-UX again
        27133 Initialise lastparen in the regexp structure
        27034 Avoid "Prototype mismatch" warnings with autouse
        26970 Make Passive mode the default for Net::FTP
        26921 Avoid getprotobyname/number calls in IO::Socket::INET
        26897,26903 Make common IPPROTO_* constants always available
        26670 Make '-s' on the shebang line parse -foo=bar switches
        26536 INSTALLSCRIPT versus INSTALLDIRS
        26379 Fix alarm() for Windows 2003
        26087 Storable 0.1 compatibility
        25861 IO::File performace issue
        25084 long groups entry could cause memory exhaustion
        24699 ICMP_UNREACHABLE handling in Net::Ping
  Built under MSWin32
  Compiled at Aug 29 2006 12:42:41
  @INC:
    C:/Perl/site/lib
    C:/Perl/lib
    .
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