Okay, without using modules: 
my ($day, $month, $year, $filename);
(undef, undef, undef, $day, $month, $year, undef) = localtime(time() -
+ (24*60*60));
$filename = sprintf("%02d-%02d-%04d.txt", $day, $month+1, $year+1900);

[download]
Season to taste.

And, yes, you really should learn to use modules. They're invaluable.

In reply to Re: Date by redcloud
in thread How to find yesterdays date (was: Date) by Anonymous Monk

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