Wednesday, April 25, 2018

JavaScript Date Methods


JavaScript Date Methods

Method   Description
getUTCDate()     Same as getDate(), but returns the UTC date
getUTCDay() Same as getDay(), but returns the UTC day
getUTCFullYear()     Same as getFullYear(), but returns the UTC year
getUTCHours()   Same as getHours(), but returns the UTC hour
getUTCMilliseconds()   Same as getMilliseconds(), but returns the UTC milliseconds
getUTCMinutes()    Same as getMinutes(), but returns the UTC minutes
getUTCMonth() Same as getMonth(), but returns the UTC month
getUTCSeconds()    Same as getSeconds(), but returns the UTC seconds
.

Date methods let you get and set date values (years, months, days, hours, minutes, seconds, milliseconds)

Date Get Methods
Get methods are used for getting a part of a date. Here are the most common (alphabetically):

Method   Description
getDate() Get the day as a number (1-31)
getDay()  Get the weekday as a number (0-6)
getFullYear() Get the four digit year (yyyy)
getHours()    Get the hour (0-23)
getMilliseconds()    Get the milliseconds (0-999)
getMinutes()      Get the minutes (0-59)
getMonth()   Get the month (0-11)
getSeconds()      Get the seconds (0-59)
getTime()      Get the time (milliseconds since January 1, 1970)
The getTime() Method
getTime() returns the number of milliseconds since January 1, 1970:

Example
<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getTime();
</script>
»
The getFullYear() Method
getFullYear() returns the year of a date as a four digit number:

Example
<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getFullYear();
</script>
»
The getDay() Method
getDay() returns the weekday as a number (0-6):

Example
<script>
var d = new Date();
document.getElementById("demo").innerHTML = d.getDay();
</script>
»
In JavaScript, the first day of the week (0) means "Sunday", even if some countries in the world consider the first day of the week to be "Monday"

You can use an array of names, and getDay() to return the weekday as a name:

Example
<script>
var d = new Date();
var days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
document.getElementById("demo").innerHTML = days[d.getDay()];
</script>
»
Date Set Methods
Set methods are used for setting a part of a date. Here are the most common (alphabetically):

Method   Description
setDate() Set the day as a number (1-31)
setFullYear() Set the year (optionally month and day)
setHours()     Set the hour (0-23)
setMilliseconds()     Set the milliseconds (0-999)
setMinutes() Set the minutes (0-59)
setMonth()   Set the month (0-11)
setSeconds() Set the seconds (0-59)
setTime() Set the time (milliseconds since January 1, 1970)
The setFullYear() Method
setFullYear() sets a date object to a specific date. In this example, to January 14, 2020:

Example
<script>
var d = new Date();
d.setFullYear(2020, 0, 14);
document.getElementById("demo").innerHTML = d;
</script>
»
The setDate() Method
setDate() sets the day of the month (1-31):

Example
<script>
var d = new Date();
d.setDate(20);
document.getElementById("demo").innerHTML = d;
</script>
»
The setDate() method can also be used to add days to a date:

Example
<script>
var d = new Date();
d.setDate(d.getDate() + 50);
document.getElementById("demo").innerHTML = d;
</script>
»
If adding days, shifts the month or year, the changes are handled automatically by the Date object.

Date Input - Parsing Dates
If you have a valid date string, you can use the Date.parse() method to convert it to milliseconds.

Date.parse() returns the number of milliseconds between the date and January 1, 1970:

Example
<script>
var msec = Date.parse("March 21, 2012");
document.getElementById("demo").innerHTML = msec;
</script>
»
You can then use the number of milliseconds to convert it to a date object:

Example
<script>
var msec = Date.parse("March 21, 2012");
var d = new Date(msec);
document.getElementById("demo").innerHTML = d;
</script>
»
Compare Dates
Dates can easily be compared.

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

Example
var today, someday, text;
today = new Date();
someday = new Date();
someday.setFullYear(2100, 0, 14);

if (someday > today) {
    text = "Today is before January 14, 2100.";
} else {
    text = "Today is after January 14, 2100.";
}
document.getElementById("demo").innerHTML = text;
»
JavaScript counts months from 0 to 11. January is 0. December is 11.

UTC Date Methods
UTC date methods are used for working UTC dates (Universal Time Zone dates):




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