function minDate(dates : any) : Date {
let min = dates[0],
obj = new Date(dates[0]);
dates.forEach(function(dt : Date, index : number) {
if (new Date( dt ) < obj) {
min = dt;
obj = new Date(dt);
}
});
return min;
}
const dates = ['2021/03/20', '2021/05/21', '2021/01/13', '2021/01/14', '2021/05/20'];
console.log(minDate(dates));
/*
run:
"2021/01/13"
*/