"badly formed number" error in csh scripts on linux

I have several .csh scripts that scroll through months and days to process daily files (eg. for MCIP). When running one such script this week on nitrate, I ran into a "badly formed number" error on days 08 and 09 -- and only on those days. Turns out, this is why:

"If your script uses comparisons of numbers that begin with a 0, CSH will interpret it as an octal number. if the number contains 8 or 9, it will fail because 8 and 9 do not exist in octal. To get around this problem, you should switch to a different shell (like bash) or use a more robust scripting language, such as Perl."
from:http://www.purdue.edu/eas/info_tech/faq/faq_linux.php#csh

My in-the-moment solution was to hardcode separate scripts for those days, but there are several possible workarounds, including switching shells or operating systems.