TypeScript Calcule dias entre datas

let startDate: string = "2021-04-01";
let date1: Date = new Date();
let date2: Date = new Date(startDate);
let timeInMilisec: number = date1.getTime() - date2.getTime();
let daysBetweenDates: number = Math.ceil(timeInMilisec / (1000 * 60 * 60 * 24));
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