$ARGV[ 0 ] =~ m[^(\d{4})(\d{2})(\d{2})] or die "Bad date: $ARGV[ 0 ]";
print "$ARGV[0] is NOT a month end day" 
    if $3-28-substr(' 303232332323',$2,1)-($2==2and not$1%4xor$1%100xo
+r$1%400);
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