I am surprised that nobody yet has suggested that you take a look at something relatively famous called the 'Schwartzian Transform', a quite powerful algorithm for sorting slightly complicated data such as the one you have, especially if you have a lot of data (where is is much faster, because it avoids duplicating some part of processing many times), but also quite practical in my view even if your data is quite small. It is sufficiently well known to have an article in Wikipedia (in many languages) and pages in many thousands of other sites. Just google it, or, if you prefer or are not completely convinced that Google is your friend these days, go to some initial pointers on it on Perlmonks:

What is "Schwarzian Transform" (aka Schwartzian)

Schwartzian Transform

Sorting dates with the Schwartzian Transform