These are all multi-fandom challenges!
purimgifts challenge: Signups open now; close on February 8 (next Wednesday)
Assignments sent out February 9
Assignments due March 3
Pinch hits due March 4-6
Postings made (actually, revealed by mods) March 7, 8, and 9
Author reveal March 10
This one is a little involved. See the rules post for the requirements for the fandom/character requests. Each day's post is one ficlet, 300-1000 words (no more than 1000 words!), and one graphic "of some kind." (Actually, you can make more graphics than that, if you like.)
rarewomen challenge: Signups open now; close February 8 (this coming Wednesday)
Assignments sent out around February 15
Assignments due April 30
Minimum story length: 1000 words
This signup process for this one looks pretty arcane. On the other hand, there are some nifty fandoms in the allowable list, and it looks like at least 100 people have signed up so far.
springkink XI: Prompt collecting now open; closes February 29
Prompt list(s) go(es) up by March 3, 2012 ( (it usually takes several posts ... )
Claiming begins on March 10, 2012 at 9:00 a.m. EST
(IIRC, claiming pretty much stays open up to the due date of the prompt)
Stories/Art will be posted between May 1 and May 31
You may claim as many prompts as you think you can handle. Each prompt may be claimed 6 times (3 claims for fiction, 3 claims for art). The minimum story length is 100 words and no, you need not write smut (I have seen things rated anywhere from G to NC-17).
From my point of view, this is pretty nifty in terms of spacing out deadlines - there are due dates of early March, late April, and throughout May.