my @dates = qw( 2001-12-24 1999-03-2 2004-04-23 );
  print join(', ', sort { $b cmp $a } @dates );

##</code><code>##

  2004-04-23, 2001-12-24, 1999-03-2

##</code><code>##

sort { $a->{date} cmp $b->{date} } @$array

##</code><code>##

grep { $_->{date} ge $today } ...

##</code><code>##

 ( ... )[0]->{isnext} = 1;

##</code><code>##

(grep {$_->{date} ge $today} sort {$a->{date}cmp $b->{date} } @$array)[0]->{isnext} = 1;

##</code><code>##

my $today = '2001-03-28';
my $array = [
  { date => '2001-02-01' },
  { date => '1999-04-09' },
  { date => '2001-03-31' }, 
  { date => '2001-03-24' },
  { date => '2001-04-15' },
];


# find the smallest date larger than or equal to today.

# set the isnext flag 
(grep { $_->{date} ge $today } sort { $a->{date} cmp $b->{date} }  @$array)[0]->{isnext} = 1;

# print all out and indicate which one is next...
for my $e (@$array) {
  print "\n", $e->{date};
  print " this is next" if $e->{isnext};
}

# alternatively : 
my $thenext = (grep { $_->{date} ge $today } sort { $a->{date} cmp $b->{date} }  @$array)[0];
print "\nThe next date is: $thenext->{date}\n";