Actually the best idea would be to look at Schwartz's Learning Perl (3rd) book.

It tells you in Chapter 15 how to make perl  sort according to what you want. The default is the (weird) ASCIIbetical method. In that method Caps come before lower case letters, and punctuation comes in all different places. By using Chapter 15's lesson you can make it sort to however YOU want it to (yes, even your date idea).

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Originally posted as a Categorized Answer.