To repeat one of my earlier suggestions:

Why on Earth are you testing $ref->{date} eq $Date inside of the inner foreach loop? If they're not equal, skip the inner foreach loop altogether!

Admittedly, this was probably more important back when you were using a regex match instead of eq. But it could still make a big difference...

Update: And while I'm at it, these lines:

  foreach $key (keys %hash) {
    $ref = $hash{$key};
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Can be replaced with this:

  foreach $ref (values %hash) {
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buckaduck