/// /// import * as DayPicker2 from "react-day-picker"; function isSunday(day: Date) { return day.getDay() === 0; } // make sure global variable version works function MyComponent2() { return } DayPicker.DateUtils.clone(new Date()); DayPicker.DateUtils.isDayInRange(new Date(), {from: new Date()}); // make sure imported version works function MyComponent() { return } DayPicker2.DateUtils.clone(new Date()); DayPicker2.DateUtils.isDayInRange(new Date(), { from: new Date() });