I tried to use "Run Real JavaScript" in BTT and put the code below.
(async() => {
let year = 2021;
let month = 1;
let day = 40;
let newDate = new Date(year + "/" + month + "/" + day);
let status = newDate instanceof Date && !isNaN(newDate.getTime());
returnToBTT('');
})()
status returns "true" which is wrong because "2021/1/40" is an invalid date, but if I run it in Google Console, it returns "false" which is correct.
What is wrong?
let year = 2021;
let month = 1;
let day = 40;
let newDate = new Date(year + "/" + month + "/" + day);
let status = newDate instanceof Date && newDate.getFullYear() == year && (newDate.getMonth() + 1) == month && newDate.getDate() == day;