I assume the dates that are given are the dates on which your articleship period is to be counted. They are the dates as mentioned for articleship period in your various foms.
As per the dates mentioned you are not completing 18 months of Articleship before the exam and hence you will not be eligible to give the exams. You will be completing 17 months & 24 days till 31st Oct 2009. The leaves are of no relevance if you would be completing 18 months as you can ask your present employer to certify that you have worked for 15 months and taken only 3 months leave including 19 days leave of your prevous employer.