The worst bombing was during the night of November 14th 1940. My mum's dad was killed that night. He had gone to work a night shift in a small factory in Windsor St, Spon End. Took a direct hit. But there were other bombings as well. As for researching time frames etc, there's a very good record here..... Family Tree Researcher: Coventry Blitz Resource Centre (familyresearcher.co.uk)
Coventry's Blitz: Some blitz statistics
The Coventry Blitz (Moonlight Sonata), 14th November 1940 and Air Raids of World War Two.
Managed to find what I was after here.