I'm an occasional perler myself and I bet that others or myself would find that code you mention to be useful, at least for the black book of snippets. Would you mind pasting?
rg '<filter pattern>' <logfile> | \
perl -MData::Dumper -n -e '
m/\d{2}:\d{2}:([\d.]+)/;
if ($last) {
$diff = $1 - $last;
print "$diff\n";
$hist{$diff} += 1;
}
$last = $1;
END {
$Data::Dumper::Sortkeys = true;
print Dumper(\%hist);
}
'