EC announces poll dates for five states * Kerala polls on 13 April * Model code of conduct comes into effect * West Bengal polls in 6 phases, 18, 23, 27 April and 3, 7, 10 May * Assam polls in two phase, 4 & 11 April * Puducherry polls on 13 April * Tamil Nadu polls on 13 April * Counting day for all five states on 13 May