#!/bin/perl
# Get todays date and return yesterdays as yymmdd 
# Note that mm == 1 == Jan
#
sub yesterday {
    local($oneday) = (60*60*24);
    local($sec,$min,$hr,$md,$mo,$yr) = localtime(time() - $oneday);
    sprintf "%02d%02d%02d", $yr, ++$mo, $md;
}

yesterday()