my $date = $day | ($month<<5) | ($year<<9);
my $time = $second | ($min<<5) | ($hour<<11);
my $fat32 = sprintf "0x%08x", $time | ($date<<16);

##</code><code>##

my $bits = sprintf "%07b%04b%05b%05b%06b%05b",
    $year, $month, $day, $hour, $min, $sec;
my $fat32 = sprintf "0x%08x", oct( "0b$bits" );

##</code><code>##

Sat Jul 25 16:09:52 2015
Binary:
year    mon  day   hour  min    sec
0100011 0111 11001 10000 001001 11010
     35    7    25    16      9    26
   2015                            52
Hex:
0100 0110 1111 1001 1000 0001 0011 1010
0x46f9813a