Oh cool. I found this on Reddit here that explains the Turk schedule. This was posted three years ago, but hopefully its right.
The official reference calendar for reasons why mturk is so slow
Jan 1-15-Post holiday lull
Jan 15-31-School just started give the students time to settle in before starting projects
Feb 1-21st-Presidents day lull
Feb 22nd-April 8th-Dreaded Spring break week from hell and/or easter lull
April 8-April 30th-Slow stretch before final projects at colleges
May 1st-15th-School is almost out
May 15-May 31st-Memorial day Lull
June 1-30-What do you expect, school is out
July 1-15 4th of july lull
July 15th-August 31-I expected it to be bad, but this summer slump is worse than ever, is mturk closing down?
September 1st-September 10th Labor day lull
September 10-October 15th-This should be back to normal but is worse than ever, either school projects havent started or mturk is closing down
October 15th-November 15th-Too many new turkers
November 16th-30 Thanksgiving lull
December 1st to December 20th-Too many new turkers, too many general turkers due to holidays
December 21st to 31st-Christmas and New years slowdown
Hopefully this isn't right. I really don't want to get an actual job.