Woodford County/Ilford County is a different 11 plus exam to Chelmsford County High School for Girls and Westcliff High School for Girls. The two are different LEA's and have never been at the same time.
The exam for Chelmsford and Westcliff is run by the CSSE. It always used to be in November but was brought forward (due to new Government rules) to September this year (Sat 22nd Sept 2012). The date for next year has not been released yet but I would be surprised if it was changed again after only one year. The schools open evenings for prospective students were in July.http://www.csse.org.uk/
Woodford County/Ilford County I'm afraid I know little about. I believe the exam was the 3rd September this year (used to be ?December) try looking at the Essex - Redbridge section of the forum for more information.