use integer;

#...code ommited; obtain $days from FROM_DAYS()
#                 and $birth_year from database

my $this_year;
my @time;
my $raw_years;
my $num_leaps;
my $int_years;
my $float_years;

@time = localtime(time);
$this_year = $time[5] + 1900;
$raw_years = $this_year - $birth_year;
$num_leaps = $raw_years / 4;
$days += $num_leaps;

$int_years = $days / 365;

no integer;

$float_years = $days / 365;

if ($int_years == $float_years) {
   print "Today's your birthday!";
}

#...Then do whatever else you're going to do