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JavaScript Date Date

JavaScript Java 1970 1 1 UTC Unix 1970 1 1 UTC

Date -100,000,000 100,000,000

Date

const dateObjectName = new Date([parameters]);

dateObjectName Date

new Date

parameters

today = new Date();
YYYY-MM-DDTHH:mm:ss.sssZxmas95 = new Date("1995-12-25") 0
xmas95 = new Date(1995, 11, 25)
xmas95 = new Date(1995, 11, 25, 9, 30, 0);

Date

Date

set Date
get Date
to Date
parse UTC Date

getset getDay setDay

0 59
0 23
0 6
1 31
1900

const xmas95 = new Date("1995-12-25");

xmas95.getMonth() 11xmas95.getFullYear() 1995

getTime setTime getTime Date

const today = new Date();
const endYear = new Date(1995, 11, 31, 23, 59, 59, 999); // 
endYear.setFullYear(today.getFullYear()); // 
const msPerDay = 24 * 60 * 60 * 1000; // 
let daysLeft = (endYear.getTime() - today.getTime()) / msPerDay;
daysLeft = Math.round(daysLeft); //

today Date endYear Date today endYear getTime

parse Date parse setTime ipoDate

const ipoDate = new Date();
ipoDate.setTime(Date.parse("Aug 9, 1995"));

JSClock()

function JSClock() {
  const time = new Date();
  const hour = time.getHours();
  const minute = time.getMinutes();
  const second = time.getSeconds();
  let temp = String(hour % 12);
  if (temp === "0") {
    temp = "12";
  }
  temp += (minute < 10 ? ":0" : ":") + minute;
  temp += (second < 10 ? ":0" : ":") + second;
  temp += hour >= 12 ? " P.M." : " A.M.";
  return temp;
}

JSClock time Date time getHoursgetMinutes getSeconds hourminute second

time temp hour % 12 12 hour 0 temp 12 12:00 0:00

temp minute minute 10 0 temp

hour 12 P.M. tempA.M. temp

MDN

2025716 MDN

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