There is a clichéd view of history encouraged by bad teaching that presents the subject as the memorising of long lists of dates that somebody has designated as being significant, 55 BC, 1066, 1492, 1687, 1859, 1914 etc., etc. Now whilst in reality history is much more concerned with what happened and why it happened than with when it happened dates are the scaffolding on which historians hang up their historical facts for inspection.
When presenting biographies of scientists two key dates that the historical biographer has to remember are those of the birth and the death of her or his subject. One of my favourite Renaissance mathematici mathematics teacher, astronomer, astrologer, cartographer and globe maker, Johannes Schöner, about whom I have already blogged in the past, made life easier for historians by dying on his seventieth birthday. He was born on 16th January 1477 in Karlstadt am Main and died on 16th January 1547 in Nürnberg. This means one only has to remember his birthdate and them simply add seventy to get his date of death.