12 October 2016
you need to pay the excise duty on or before 5th of subsequent month. online website. https://cbec-easiest.gov.in/EST/InputPageForEPaymentServlet
and, for return, due date is 10th of subsequent month - website is https://www.aces.gov.in/REGASE/switch.do?prefix=/ui/jsp/common&page=/firstlogin.do