Hướng dẫn và ví dụ JavaScript Date

let date = new Date("December 25, 2017 23:15:00");

var day = date.getDate();

console.log(day); // 25

let date = new Date("December 25, 2017 11:15:00");// Monday

var day = date.getDay();

console.log(day); // 1

let date = new Date("December 25, 2017 11:15:00");// Monday

var year = date.getFullYear();

console.log(year); // 2017

let date = new Date("December 25, 2017 22:10:00");

let hour = date.getHours();

console.log(hour); // 22

let now = new Date();

console.log(now);// Ex: 2018-11-25T05:52:20.490Z

console.log("getMilliseconds() : " + now.getMilliseconds()); // 490

let now = new Date();

console.log(now);// Ex: 2018-11-25T05:58:20.178Z

console.log("getMinutes() : " + now.getMinutes()); // 58

let now = new Date();

console.log(now);// Ex: 2018-11-25T05:58:20.178Z

let month = now.getMonth(); // 10

console.log(month); // 10

let now = new Date();

console.log(now);// Ex: 2018-11-25T06:06:24.211Z

console.log("getSeconds() : " + now.getSeconds()); // 24

let now = new Date();

console.log(now);// Ex: 2018-11-25T06:14:59.213Z

console.log("getTime() : " + now.getTime()); // 1543126499213

// Vietnam: UTC+07:00
let now = new Date();

let timezoneOffset = now.getTimezoneOffset();

console.log(timezoneOffset); // -420

// This example test in Locale: Vietnam UTC+7:00

let date = new Date("December 25, 2017 01:15:00");

let day = date.getDate();

console.log(day); // 25  (Test in Vietnam UTC+7:00)

let utcDay = date.getUTCDate();

console.log(utcDay); // 24  (UTC)

// This example test in Locale: Vietnam UTC+7:00

let date = new Date("December 25, 2017 01:15:00"); // Monday

let day = date.getDay();

console.log(day); // 1


let utcDay = date.getUTCDay();

console.log(utcDay); // 0

// This example test in Locale: Vietnam UTC+7:00

let date = new Date("January 01, 2019 01:15:00");

var year = date.getFullYear();

console.log(year); // 2019


var utcYear = date.getUTCFullYear();

console.log(utcYear); // 2018

// This example test in Locale: Vietnam UTC+7:00

let now = new Date();

console.log(now);// Ex: 2018-11-25T07:29:59.575Z

let hour = now.getHours();

console.log(hour); // 14


let utcHour = now.getUTCHours();  

console.log(utcHour); // 7

// This example test in Locale: Vietnam UTC+7:00

let now = new Date();

console.log(now);// Ex: 2018-11-25T07:35:06.442Z

console.log("getUTCMinutes() : " + now.getUTCMinutes()); // 35

// This example test in Locale: Vietnam UTC+7:00

let now = new Date();

console.log(now);// Ex: 2018-11-25T07:39:03.222Z

console.log("getUTCMilliseconds() : " + now.getUTCMilliseconds()); // 222

// This example test in Locale: Vietnam UTC+7:00

let date = new Date("January 01, 2019 01:15:00");

console.log(date);// 2018-12-31T18:15:00.000Z

// January 2019 (Vietnam)
let month = date.getMonth(); // 0

console.log(month); // 0

// December 2018 (UTC)
let utcMonth = date.getUTCMonth(); // 11

console.log(utcMonth); // 11

// This example test in Locale: Vietnam UTC+7:00

let now = new Date();

console.log(now);// Ex: 2018-11-25T06:06:24.211Z

console.log("getUTCSeconds() : " + now.getUTCSeconds()); // 24

let date = new Date("February 25, 2017 23:15:00"); // 25/02/2017

date.setDate(18);

console.log(date); // 2017-02-18T16:15:00.000Z

// ??
date.setDate(31);

console.log(date); // 2017-03-03T16:15:00.000Z

let date = new Date();

console.log(date);// Ex: 2017-02-25T16:15:00.000Z

date.setFullYear(2015, 3, 19);

console.log(date); // 2018-12-19T16:15:00.000Z


date.setFullYear(2014, 10);

console.log(date); // 2018-12-25T16:15:00.000Z


date.setFullYear(2013);

console.log(date); // 2019-12-25T16:15:00.000Z

let date = new Date();

console.log(date);// Ex: 2018-11-25T17:42:01.751Z

date.setMonth(3, 19);// Month, day of month

console.log(date); // 2018-04-18T17:42:01.751Z


date.setMonth(10); // Month

console.log(date); // 2018-11-18T17:42:01.751Z

let date = new Date();

console.log(date);// Ex: 2018-11-25T17:36:18.955Z

date.setHours(22, 11, 03, 555); // hours, minutes, seconds, milliseconds

console.log(date); // 2018-11-26T15:11:03.555Z


date.setHours(13, 10);// hours, minutes

console.log(date); // 2018-11-26T06:10:03.555Z

var date = new Date( "Aug 28, 2008 23:30:00" );

date.setTime( 5000000 );
console.log( date ); // 1970-01-01T01:23:20.000Z

let date = new Date( );

var str = date.toDateString();

console.log(str); // Thu Nov 29 2018

var dateobject = new Date(1993, 6, 28, 14, 39, 7);

console.log( dateobject.toTimeString() ); // 14:39:07 GMT+0700 (GMT+07:00)

// This example test in Locale: Vietnam UTC+7:00

var dateobject = new Date(1993, 6, 28, 14, 39, 7);

console.log( dateobject.toString() ); // Wed Jul 28 1993 14:39:07 GMT+0700 (GMT+07:00)

// This example test in Locale: Vietnam UTC+7:00

var dateobject = new Date(1993, 6, 28, 14, 39, 7);

console.log( dateobject.toString() ); // Wed Jul 28 1993 14:39:07 GMT+0700 (GMT+07:00)

console.log( dateobject.toUTCString() ); // Wed, 28 Jul 1993 07:39:07 GMT

<!DOCTYPE html>
<html>
   <head>
      <meta charset="UTF-8">
      <title>toLocaleDateString()</title>
      <script>
         var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

         var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };

         console.log(date.toLocaleDateString('de-DE', options));
         // expected output: Donnerstag, 20. Dezember 2012

         console.log(date.toLocaleDateString('ar-EG', options));
         // expected output: الخميس، ٢٠ ديسمبر، ٢٠١٢

         console.log(date.toLocaleDateString('ko-KR', options));
         // expected output: 2012년 12월 20일 목요일
      </script>
   </head>
   <body>
      Show informations in the Console.
   </body>
</html>

<!DOCTYPE html>
<html>
   <head>
      <meta charset="UTF-8">

      <title>toLocaleTimeString()</title>
      <script>
         var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

         var options = {} // {hour: "2-digit", minute: "2-digit", second: "2-digit"}

         console.log(date.toLocaleTimeString('de-DE', options));
         // expected output: 10:00:00

         console.log(date.toLocaleTimeString('ar-EG', options));
         // expected output: ١٠:٠٠:٠٠ ص

         console.log(date.toLocaleTimeString('ko-KR', options));
         // expected output: 오전 10:00:00
      </script>
   </head>
   <body>
      Show informations in the Console.
   </body>
</html>

<!DOCTYPE html>
<html>
   <head>
      <meta charset="UTF-8">

      <title>toLocaleString()</title>
      <script>
         var date = new Date(Date.UTC(2012, 11, 20, 3, 20, 59));

         //  { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric',
         //     hour: "2-digit", minute: "2-digit", second: "2-digit"}
         var options = {}; // Default options

         console.log(date.toLocaleString('de-DE', options));
         // expected output: 20.12.2012, 10:20:59

         console.log(date.toLocaleString('ar-EG', options));
         // expected output: ٢٠‏/١٢‏/٢٠١٢ ١٠:٢٠:٥٩ ص

         console.log(date.toLocaleString('ko-KR', options));
         // expected output: 2012. 12. 20. 오전 10:20:59
      </script>
   </head>
   <body>
      Show informations in the Console.
   </body>
</html>