score:7
When Newton died, the British started the new year on March 25 (Lady Day). In 1752, the UK switched to starting the New Year on January 1. Dates between January 1 and March 25 prior to 1752 happened in different years Old Style vs. New Style.
This is all explained nicely at: Wikipedia: Old Style and New Style dates
Added (thanks to @LangLangC for the excellent link): Calendrical confusion or just when did Newton die?