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User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)

Description of problem:
The following command failed, but only for the ninth week of the year.
echo "$((`date +U` % 5))"
The `date` executable prepends an unnecessary leading zero to week 
nine (but not earlier weeks, IS THIS ALSO A BUG?). 
The following commands fail (whenever the digits 8 or 9 exist with 
the occurrance of leading zero):
echo "$((08 % 5))"
echo "$((09 % 5))"
echo "$((0800 % 5))"
echo "$((078 % 5))"
The following commands succeed
echo "$((07 % 5))"
echo "$((78 % 5))"

Version-Release number of selected component (if applicable):
exists on all versions (back to RH release 7.2)

How reproducible:
Always

Steps to Reproduce:
1.See Description
2.
3.
    

Additional info: