--- a/C4/Overdues.pm +++ a/C4/Overdues.pm @@ -283,6 +283,11 @@ C<$branchcode> is the branch whose calendar to use for finding holidays. sub _get_chargeable_units { my ($unit, $dt1, $dt2, $branchcode) = @_; + + # If the due date is later than the return date + return 0 if ( $dt1 > $dt2 ); + ## FIXME: Add unit test + my $charge_units = 0; my $charge_duration; if ($unit eq 'hours') { --