A straightforward solution is to sort at a finer granularity e.g 
use DDS;

# your $events structure here ...

@$events = sort { $a->{month} <=> $b->{month} } @$events;
@{$_->{list}} = sort { $a->{date} <=> $b->{date} } @{$_->{list}}
  for @$events;

Dump $events;

__output__

$ARRAY1 = [
            {
              list  => [
                         {
                           date => 10,
                           name => 'picnic'
                         },
                         {
                           date => 15,
                           name => 'high tea'
                         },
                         {
                           date => 23,
                           name => 'rafting'
                         }
                       ],
              month => 7,
              name  => 'July'
            },
            {
              list  => [
                         {
                           date => 12,
                           name => 'golfing'
                         },
                         {
                           date => 20,
                           name => 'retreat'
                         },
                         {
                           date => 29,
                           name => 'marathon'
                         }
                       ],
              month => 8,
              name  => 'August'
            }
          ];

[download]
HTH

_________
broquaint

In reply to Re: Sorting an AoHoH or AoHoAoH by broquaint
in thread Sorting an AoHoH or AoHoAoH by bradcathey

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.