Coming a bit late to this thread, but I just need to add a plug forMatts' criminally underused Time::Piece module. If you subtract one Time::Piece object from another, then the result is a Time::Seconds object which can be displayed in various ways. An example from the docs:

use Time::Object;
use Time::Seconds;

my $t = localtime;
$t += ONE_DAY;
    
my $t2 = localtime;
my $s = $t - $t2;
    
print "Difference is: ", $s->days, "\n";
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