Home Backend Development PHP Tutorial Detailed explanation of php timestamp (UNIX) usage

Detailed explanation of php timestamp (UNIX) usage

Jul 14, 2017 am 10:41 AM
php unix Detailed explanation

Timestamp is the number of seconds since January 1, 1970 (00:00:00 GMT). It is also called Unix Timestamp.

Unix timestamp, also known as Unix time (Unix time), POSIX time (POSIX time), is a time representation method, defined as January 1, 1970 Greenwich Time The total number of seconds since 00:00:00 to now. Unix timestamps are not only used in Unix systems and Unix-like systems, but are also widely used in many other operating systems. This article mainly introduces the usage of php UNIXtimestamp, and analyzes the related functions and usage techniques of php Unix timestamp in the form of examples, as follows:

Time stamps are the creation, modification, and access times in the file attributes . The digital timestamp service is one of the security services of the Web website, which can provide security protection for the date and time information of electronic files.

The advantage of timestamp is:

The encrypted value can be changed to prevent the value from being stolen and illegally reused, and plays the role of encryption. . Timestamps mainly rely on time and generate a unique value within an agreed period of time.

UNIX timestamp

In the UNIX system, the date and time are expressed as the time from 0:00 on January 1, 1970 to the current moment Number of seconds. This time is called a UNIX timestamp and is represented as a 32-bit binary number. This time representation method is supported in different operating systems. The same time is represented by the same UNIX timestamp in UNIX and Windows, so there is no need to convert in different systems.

The current UNIX timestamp is represented by a 32-bit binary number, and the 32-bit binary value range is (-2147483648~+2147483647). Since the system does not support negative timestamps, the current UNIX timestamp can represent The maximum time is 3:14:7 on January 19, 2038, and the timestamp of this moment is 2147483647. After this time, the number of binary digits of the UNIX timestamp needs to be extended.

PHP Gets the timestamp of a specified date

Apply the mktime() function in PHP to convert a time into UNIX timestamp value.

The syntax is as follows

mktime(hour,minute,second,month,day,year,is_dst)
Copy after login
ParameterDescription
hourOptional. Specified hours.
minuteOptional. Specified minutes.
secondOptional. Specifies seconds.
monthOptional. Specifies the numeric month.
day Optional. Specify days.
year可选。规定年。在某些系统上,合法值介于 1901 - 2038 之间。不过在 PHP 5 中已经不存在这个限制了。
is_dst

可选。如果时间在日光节约时间(DST)期间,则设置为1,否则设置为0,若未知,则设置为-1。

自 5.1.0 起,is_dst 参数被废弃。因此应该使用新的时区处理特性。

例如:

echo "时间戳:".mktime().&#39;<br>&#39;;//返回当前时间戳
echo "任意日期:".date("Y-m-d",mktime(0,0,0,2,21,1996)).&#39;<br>&#39;;
echo "当前日期: ".date("Y-m-d",mktime()).&#39;<br>&#39;;
Copy after login

运行结果为:

时间戳:1458979695
任意日期:1996-02-21
当前日期: 2016-03-26
Copy after login

获取当前时间戳

PHP通过time()函数获取当前的UNIX时间戳。

语法如下:

int time(void);

该函数没有参数,返回值为UNIX时间戳的整数值。

例如:

echo time()."<br>";//输出当前时间戳
$nextWeek = time()+(7*24*60*60);//一个星期七天,一天24小时,一个小时60分,一分60秒
echo "Now: ".date("Y-m-d")."<br>";
echo "Next Week: ".date("Y-m-d",$nextWeek);
Copy after login

运行结果为

1458980073
Now: 2016-03-26
Next Week: 2016-04-02
Copy after login

The above is the detailed content of Detailed explanation of php timestamp (UNIX) usage. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

PHP Program to Count Vowels in a String PHP Program to Count Vowels in a String Feb 07, 2025 pm 12:12 PM

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

How do you parse and process HTML/XML in PHP? How do you parse and process HTML/XML in PHP? Feb 07, 2025 am 11:57 AM

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? Apr 03, 2025 am 12:03 AM

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

PHP and Python: Comparing Two Popular Programming Languages PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

See all articles