New Delhi: Bengal's festive season runs on its own calendar, from Mahalaya through Durga Puja into Kali Puja, and brands that simply adapt their national Diwali creative for the region tend to find it doesn't land. Fortune Oil has spent the last few years recalibrating for that gap, shares Jignesh Shah, Head, Media & Digital at AWL Agri Business. The brand has moved from emotional storytelling around Durga Puja to actually showing up inside the…