Poets & Writers has one on their website (a companion to the bimonthly* print edition, with lots of good content). “Use our handy calendar to schedule your submissions to writing contests, grants, and other literary awards.”
It is very handy.
* According to definition (1.1).



Thanks for this!
Here’s another online submissions site I like to check. It’s organized by date of notice released, not by date of deadline; nevertheless, it’s helpful.
Woops. Here’s the link.
http://www.newpages.com/literary/submissions.htm
Deb Scott replied:
December 16th, 2009 at 8:38 am
I *love* NewPages. I also read their blog via reader, just about every day!