if ($file = glob(($base)."*.txt")){
   # ...
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use File::Copy ();

my $base = '/Volumes/case-sensitive/projects/monks/1190936';
my @time = (localtime)[ 5, 4, 3 ];
$time[0] += 1900;
$time[1]++;
my $dir_for_today = sprintf '%s/%04d/%02d/%02d', $base, @time;

die "destination $dir_for_today is not a directory!\n" unless -d $dir_for_today;

foreach my $file ( glob qq($base/*.txt)  ) {
    File::Copy::move $file, $dir_for_today  or  warn "Can't move $file to $dir_for_today : $!";
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use File::Copy ();
use File::Spec;

my $volume = ''; # empty string for Unix
my @dirs = ( File::Spec->rootdir, 'Volumes', 'case-sensitive', 'projects', 'monks', '1190936' );
my $base = File::Spec->catpath( $volume, File::Spec->catdir( @dirs ), '' );
my @time = (localtime)[ 5, 4, 3 ];
$time[0] += 1900;
$time[1]++;
$time[1] = sprintf '%02d', $time[1];
$time[2] = sprintf '%02d', $time[2];
my $dir_for_today = File::Spec->catdir( $base, @time );

die "destination $dir_for_today is not a directory!\n" unless -d $dir_for_today;

foreach my $file ( glob File::Spec->catfile( $base, '*.txt' ) ) {
    File::Copy::move $file, $dir_for_today  or  warn "Can't move $file to $dir_for_today : $!";
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use File::Copy ();
use File::Spec;
use Getopt::Long ();

my %config = (
    'source'      => '.',
    'destination' => undef,
    'extension'   => '.txt',
);

Getopt::Long::GetOptions( \%config, 'source=s', 'destination=s', 'extension=s' );

sub day_dir {
    my @time = (localtime)[ 5, 4, 3 ];
    $time[0] += 1900;
    $time[1]++;
    $time[1] = sprintf '%02d', $time[1];
    $time[2] = sprintf '%02d', $time[2];
    return File::Spec->catdir( @time );
}

sub source {
    my $c = shift;
    return $c->{ 'source' };
}

sub destination {
    my $c = shift;
    my $d = undef;
    if ( ! defined $c->{ 'destination' } ) {
        $d = File::Spec->catdir( $c->{ 'source' }, day_dir() );
    } else {
        $d = $c->{ 'destination' };
    }
    return $d;
}

sub extension {
    my $c = shift;
    return $c->{ 'extension' };
}

my $destination = destination( \%config );
die "destination $destination is not a directory!\n" unless -d $destination;
foreach my $file ( glob File::Spec->catfile( source( \%config ), '*' . extension( \%config )  ) ) {
    File::Copy::move $file, $destination  or  warn "Can't move $file to $destination : $!";
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

package Mover;
use File::Copy ();
use File::Spec;
use Getopt::Long ();


sub new {
    my $class = shift;
    my $self = {
        'source'      => '.',
        'destination' => undef,
        'extension'   => '.txt',
        'day_dir'     => undef,
        'warnings'    => [],
    };

    Getopt::Long::GetOptions( $self, 'source=s', 'destination=s', 'extension=s' );
    return bless $self, $class;
}


sub day_dir {
    my $self = shift;
    if ( ! defined $self->{ 'day_dir' } ) {
        my @time = (localtime)[ 5, 4, 3 ];
        $time[0] += 1900;
        $time[1]++;
        $time[1] = sprintf '%02d', $time[1];
        $time[2] = sprintf '%02d', $time[2];
        $self->{ 'day_dir' } = File::Spec->catdir( @time );
    }
    return $self->{ 'day_dir' };
}

sub source {
    my $self = shift;
    return $self->{ 'source' };
}

sub destination {
    my $self = shift;
    if ( ! defined $self->{ 'destination' } ) {
        $self->{'destination'} = File::Spec->catdir( $self->{ 'source' }, $self->day_dir() );
    }
    return $self->{'destination'};
}

sub extension {
    my $self = shift;
    return $self->{ 'extension' };
}

sub move {
    my $self = shift;
    if ( -d $self->destination() ) {
        foreach my $file ( glob File::Spec->catfile( $self->source(), '*' . $self->extension()  ) ) {
            File::Copy::move $file, $self->destination()  or  $self->warn( "Can't move $file to " . $self->destination() . " : $!\n" );
        }
    } else {
        $self->warn( $self->destination . " is not a directory!\n" );
    }
    return $self;
}

sub warn {
    my ( $self, $warning ) = @_;
    push @{ $self->{ 'warnings' } }, $warning;
    return $self;
}

sub warnings {
    my $self = shift;
    return join "\n", @{ $self->{ 'warnings' } };
}

1;

package main;

print STDERR Mover->new()->move()->warnings();