#! perl  -slw
use strict;
use POSIX qw[ strftime ];
use Math::BigInt;
use Date::Calc qw/Add_Delta_Days/;
use Benchmark qw[ cmpthese ];

sub holli {
    return POSIX::strftime(
        "%Y-%m-%d",
        localtime( ( $_[0] / 10000000 ) - 11644473600 )
    );
}

sub yours {
    my $loginTime = Math::BigInt->new( $_[ 0 ] );

    $loginTime = $loginTime / (60 * 10000000  ); # 60 seconds in a minute!
    $loginTime = $loginTime / 1440;

    my ($year,$month,$day) = Add_Delta_Days( 1601, 1, 1, $loginTime );
    return "$year-$month-$day\n";
}

our $lastLoginTime = '127912653523035916';

cmpthese -1, {
    yours => q[ my $dateStr = yours( $lastLoginTime ); ],
    holli => q[ my $dateStr = holli( $lastLoginTime ); ],
}

__END__
holli: 2006-05-05
yours: 2006-5-5


c:\test>junk8
          Rate yours holli
yours   3150/s    --  -98%
holli 161606/s 5030%    --