Day of next or previous year

Let's get a date object containing January 21st of next year. To do this, add one to the current year:

javascriptlet now  = new Date();
let date = new Date(now.getFullYear() + 1, 0, 21);

Задание 1

Determine what day of the week will be December 31 of next year.

Задание 2

Determine what day of the week will be one year later on the same date as today.

Задание 3

Determine what day of the week was a year ago on the same date as today.