Coming directly to you from the Horrible-But-Works department is this monstrosity:

#!/usr/bin/env perl
use strict;
use warnings;
use Digest::SHA 'sha512256_hex';

my @weekdays = qw/Monday Saturday Thursday/;

print join ",", map { $_->[0] }
sort { $a->[1] cmp $b->[1] }
map { [$_, substr (sha512256_hex (substr (lc ($_), 1, 7)), 26, 1)] } @
+weekdays;
[download]