use POSIX 'strftime';

my $now = time;
my $then = $now + (20 * 86_400); # 86,400 seconds in a day
my $then_str = strftime('%d %B %Y', localtime($then));
print "In 20 days time it will be $then_str\n";

##</code><code>##

use POSIX 'strftime';

print "In 20 days time it will be ",
      strftime('%d %B %Y', localtime(time + 20 * 86_400)),
      "\n";