See e.g. the British transition from Julian to Gregorian calendars, in which eleven days of September 1752 were not observed in England: https://en.m.wikipedia

See e.g. the British transition from Julian to Gregorian calendars, in which eleven days of September 1752 were not observed in England: https://en.m.wikipedia.org/wiki/Calendar_(New_Style)_Act_1750 https://en.m.wikipedia.org/wiki/Calendar_(New_Style)_Act_175... IIRC, that event is the reason SQLServer's datetime type is only good back to 1753, and thus why you should use datetime2 for dealing with older historical dates: https://database.guide/datetime-vs-datetime2-in-sql-server-whats-the-difference/ https://database.guide/datetime-vs-datetime2-in-sql-server-w...