date meaning in javascript code example

Example 1: javascript date methods

var d= new Date();
d.getFullYear();//Get the year as a four digit number (yyyy)
d.getMonth();//Get the month as a number (0-11)
d.getDate();//Get the day as a number (1-31)
d.getHours();//Get the hour (0-23)
d.getMinutes();//Get the minute (0-59)
d.getSeconds();//Get the second (0-59)
d.getMilliseconds();//Get the millisecond (0-999)
d.getTime();//Get the time (milliseconds since January 1, 1970)

Example 2: javascript date

const d = new Date();
d.getFullYear(); // 2020
d.getMonth(); // October
d.getDate(); // 4
d.getHours(); // 11
d.getMinutes(); // 20
d.getSeconds(); // 12
d.getMilliseconds(); // 0
d.getTime(); // ????????????