Google reports invalid date

[makevalue]

I am fixing an older site before upgrading to Joomla 2.5. I downloaded the latest version for Joomla 1.5/. It installed fine.

I submitted this link to Google: http://www.hoapulse.com/index.php?option=com_xmap&sitemap=1&view=xml. Google gives me this message back: An invalid date was found. Please fix the date or formatting before resubmitting.

How do I resolve this?

Thanks,
Steve