I can tell you just by going through the month of January with WhatLinksHere reports that we are missing a lot of in-universe dates — not to mention BTS ones.
Just to give you one example, a good deal of The Witch Hunters happens on specific dates. The chapters are in fact titled by date. So we know what happens on 14 January 1693, 16 January 1692, 11 January 1692, 15 January 1691, and a host of other specific dates.
A lot of what you're currently marking with {{delete}} just needs a little bit more research.