Here is one possiblity 
$zipfile =~ /(A|B)FILE_([0-9]+)/;
$day = $2;

[download]
However if you are just looking for digits try:
$zipfile =~ /([0-9]+)[^0-9]?/;
$day = $1;

[download]

In reply to Re: A better regex by injunjoel
in thread A better regex by williamp

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