use strict;
use warnings;
use DateTime;
chomp(my $input = <STDIN>);
my ($num, $what) = split " ", $input;
my $now = DateTime->now->set_time_zone("Europe/Berlin");
if ($what =~ m/^min/i) {
    $what = "minutes";
}
elsif ($what =~ m/^st/i) {
    $what = "hours";
}

elsif ($what =~ m/^tag/i) {
    $what = "days";
}
# ...

my $new_date = $now->add( $what => $num );
print "$new_date\n";