How to get the day of the week when entering a date?

Question

JavaScript

You need to create a function that, when you enter a date, will show what day of the week it was. Time period August 7 - September 8. The calendar is not ours. you have to generate it yourself.
I tried to do it through the generation of an associative array, but I run into the problem of how to avoid the program stupor when moving to the next month (September, for example), if the transition occurs in the middle of the week.

Answer 1

Why bother with associative arrays when ES6 has a standard method
date.toLocaleString('ru', {weekday: 'long'})