Although I can understand the humor behind the question, I can't agree with the official result. 😉
First, by 1700, the Gregorian calendar had been adopted by most of Europe (including Italy, Portugal, Spain, France, Austria, Germany, Poland, Scotland, Island, Greenland) and most of the colonies of South and Central America. So for the official answer to have a chance of being right, the question should have mentioned the date was about an event in the English colonies or in England.
Furthermore, the datetime2 is storing dates according to the Gregorian calendar. It is its only purpose.
It's not because a date is older than the adoption of a calendar in a certain country or even the invention of said calendar (1582 for the Gregorian calendar) that you can't express that date in the calendar. A calendar is merely a referential and scientifically, we can express in it whatever date we want.
Such an expression of a date becomes invalid only if you are in a very specific historic setting, like checking dates on correspondences dating from that period, because then the date doesn't make sense from the point of view of the writer of such a correspondence. We are hardly in that case when storing data in database unless you have a time machine and decide to set up a database in the past. :hehe: