Use of date

ECMAScript Of Date Type reference Java In earlier versions java.util.Date. So ,Date Type will date
Save as self coordinated universal time （UTC,Universal Time Coordinated） Time 1970 year 1 month 1 Midnight （ zero hour ） So far
Milliseconds elapsed . Using this storage format ,Date Types can be expressed precisely 1970 year 1 month 1 Before and after 285 616 Year of
date .
To create a date object , Just use new Operator to call Date Constructors ：

Date.now(); 
let date1 = new Date(2019, 0, 1); // 2019  year  1  month  1  Japan 
let date2 = new Date(2019, 1, 1); // 2019  year  2  month  1  Japan 
var date = new Date()
console.log(date.getFullYear());//2022
console.log(date.getMonth());//6  It's actually 7 month 
console.log(date.getDate());//27

console.log(date.getDay());//3
console.log(date.getHours());//9
console.log(date.getMinutes());//25
console.log(date.getSeconds());//15
console.log(date.getMilliseconds());//904
console.log(date.getTime());//1658885190098
console.log(Date.now());// 1658885190098

console.log(new Date(2022, 6).getMonth()); // 6
console.log(new Date(2022, 6).getDate()); // 1
console.log(new Date(2022, 6, 0).getDate()); //  In fact, it represents 6 Monthly 30 God 
console.log(new Date(2022, 7, 0).getDate()); //  In fact, it represents 7 Monthly 31 God 
console.log(new Date(2022, 12, 0).getDate()); //  In fact, it represents 12 Monthly 31 God 
console.log(new Date(2022, 14, 0).getDate()); //  In fact, it represents 2023 year 2 Monthly 28 God