I have updated the timeline and the day-by-day calendar to indicate that the Battle of Hogwarts was on 2 May. Unfortunately, Jo wasn’t clear about which day of the Battle was 2 May, since the start of hostilities was the evening of one day and the final confrontation was sunrise on the next. For now, I’ve decided to place the final climactic battle in the Great Hall on the second of May. Hopefully we’ll get some clarification on that soon from Jo and be able to be more precise.
New abbreviations being used in the Lexicon are PC1 and PC2 for the two parts of the Pottercast interview, TBB for the Tales of Beedle the Bard, with individual stories indicated with a forward slash and the abbreviation for the story (e.g. TBB/FFF is the Fountain of Fair Fortune), and YL for “J.K. Rowling: A Year in a Life”. For a complete list of abbreviations and sources, see the Site Sources page.
UPDATE: Roonwit pointed out that the actual battle didn’t start until midnight, when Voldemort’s first ultimatum expired. That means we can firmly place the Battle of Hogwarts on May 2, from midnight until sunrise. Thanks! I’ll edit the timeline to make that clear.