What day of the week was October 10 1582?

Answer 1

In many countries, there was no October 10, 1582. That was the month that the Gregorian calendar was put into use for the first time, so in many places, the day after Thursday, October 4, 1582 Julian calendar was Friday, October 15, 1582 Gregorian calendar.

Although it was not in use until five days later, October 10, 1582 is a Sunday on the Gregorian calendar. On the Julian calendar it is a Wednesday.