Showing posts with label JavaScript Date Object. Show all posts
Showing posts with label JavaScript Date Object. Show all posts

Wednesday, August 29, 2012

JavaScript Date Object

Try it Yourself - Examples

Return today's date and time
How to use the Date() method to get today's date.

Use getFullYear() to get the year.

getTime() returns the number of milliseconds since 01.01.1970.

How to use setFullYear() to set a specific date.

How to use toUTCString() to convert today's date (according to UTC) to a string.

Use getDay() and an array to write a weekday, and not just a number.

Display a clock
How to display a clock on your web page.

Complete Date Object Reference

For a complete reference of all the properties and methods that can be used with the Date object, go to our complete Date object reference.
The reference contains a brief description and examples of use for each property and method!

Create a Date Object

The Date object is used to work with dates and times. 

Date objects are created with the Date() constructor.

There are four ways of initiating a date:

new Date() // current date and time
new Date(milliseconds) //milliseconds since 1970/01/01
new Date(dateString)
new Date(year, month, day, hours, minutes, seconds, milliseconds)

Most parameters above are optional. Not specifying, causes 0 to be passed in.

Once a Date object is created, a number of methods allow you to operate on it. Most methods allow you to get and set the year, month, day, hour, minute, second, and milliseconds of the object, using either local time or UTC (universal, or GMT) time.

All dates are calculated in milliseconds from 01 January, 1970 00:00:00 Universal Time (UTC) with a day containing 86,400,000 milliseconds.

Some examples of initiating a date:

var today = new Date()
var d1 = new Date("October 13, 1975 11:13:00")
var d2 = new Date(79,5,24)
var d3 = new Date(79,5,24,11,33,0)

Set Dates

We can easily manipulate the date by using the methods available for the Date object.

In the example below we set a Date object to a specific date (14th January 2010):

var myDate=new Date();

And in the following example we set a Date object to be 5 days into the future:

var myDate=new Date();

Note: If adding five days to a date shifts the month or year, the changes are handled automatically by the Date object itself!

Compare Two Dates

The Date object is also used to compare two dates.

The following example compares today's date with the 14th January 2100:

var x=new Date();
var today = new Date();

if (x>today)
  alert("Today is before 14th January 2100");
  alert("Today is after 14th January 2100");