JS related functions for obtaining time and conversion between timestamp and time and date_javascript skills

Conversion of timestamps and time and dates is a common operation. Here is a code example to introduce how to convert them to each other.

Before studying this article, let me introduce to you the Date() constructor parameters in javascript:

Everyone must be familiar with the Date object. Using the Date() constructor to create a time object is the most basic operation, for example:

var theDate=new Date();
theDate.getDate();

Use the above code to get the day of the current date.

The above is the simplest application of the Date() constructor. The Date object has multiple constructors, which are briefly listed below:

new Date()
new Date(milliseconds)
new Date(datestring)
new Date(year, month)
new Date(year, month, day)
new Date(year, month, day, hours)
new Date(year, month, day, hours, minutes)
new Date(year, month, day, hours, minutes, seconds)
new Date(year, month, day, hours, minutes, seconds, microseconds)

The following is a brief analysis of the above constructors.

1.new Date(), when there are no parameters, the current time and date object is created.

2.new Date(milliseconds), when the parameter is a number, then this parameter is a timestamp, which is regarded as milliseconds. Create a time and date object with the specified milliseconds from January 1, 1970.

3.new Date(datestring), this parameter is a string, and this string must be converted using Date.parse().

4. The following six constructors are precise definitions:

1).year is an integer. If it is 0-99, then add 1900 to this and return everything else as is.
2).month, is an integer, ranging from 0-11.

3.day is an integer, ranging from 1-31.

4.hours is an integer, ranging from 0-23.

5.minutes is an integer, ranging from 0-59.

6.seconds is an integer, ranging from 0-59.

7.microseconds is an integer, ranging from 0-9999.

Code example:

var d1=new Date();
var d2=new Date(1320336000000);
var d3=new Date("2013-8-20 18:20:30");
var d4=new Date(2013,7,26);

1. Convert time and date to timestamp:

Now there is such a time and date: "2013/5/12 20:10:20". Let's convert it into timestamp form:

The code is as follows:

var dateStr="2013/5/12 20:10:20";
var date=new Date(dateStr);
console.log(date.getTime()); 

Use the getTime() function to obtain the timestamp of the specified time and date object.

Next, I will introduce to you the getTime() method of the Date object in javascript

Definition and usage of getTime() method:

This method returns the number of milliseconds between the current time and January 1, 1970.

Note: This method needs to be called using a Date object.

Click to see more related Date object methods and properties.

Grammar structure:

dateObject.getTime()

Example code:

var myDate=new Date()
console.log(myDate.getTime())

The above code can output the number of milliseconds between the current time and January 1, 1970.

In fact, there are many other methods, which I won’t introduce here. You only need to know this method, and you can slowly accumulate the others by yourself.

2. Convert timestamp to event date:

Example code 1:

var date=new Date(1368360620000);
console.log(date.toLocaleString()); 

The definition and usage of toLocaleString() method of JavaScript’s Date object:

This method can convert the Date object into a string according to the local time and return the string.

Note: This method needs to be called with an instance of the Date object.

Grammar structure:

dateObject.toLocaleString()

Example code:

var d=new Date();
console.log(d.toLocaleString());

Let’s talk about the toLocaleString() method of JavaScript’s Date object

Definition and usage of toLocaleString() method:

This method can convert the Date object into a string according to the local time and return the string.

Note: This method needs to be called with an instance of the Date object.

Grammar structure:

dateObject.toLocaleString()

Example code:

var d=new Date();
console.log(d.toLocaleString());

Example 2:

function formatDate(now)
{ 
var year=now.getYear(); 
var month=now.getMonth()+1; 
var date=now.getDate(); 
var hour=now.getHours(); 
var minute=now.getMinutes(); 
var second=now.getSeconds(); 
return year+"-"+month+"-"+date+" "+hour+":"+minute+":"+second; 
} 
var d=new Date(1368360620000); 
console.log(formatDate(d));