JavaScript version
isWeekday.js
// `date` is a Date object
const isWeekday = (date = new Date()) => date.getDay() % 6 !== 0;TypeScript version
isWeekday.ts
const isWeekday = (date = new Date()): boolean => date.getDay() % 6 !== 0;// `date` is a Date object
const isWeekday = (date = new Date()) => date.getDay() % 6 !== 0;const isWeekday = (date = new Date()): boolean => date.getDay() % 6 !== 0;