Add
date_default_timezone_set(PRC); /*把时间调到北京时间,php5默认为格林威治标准时间*/ date () a: "am"或是"pm" A: "AM"或是"PM" d: 几日,两位数字,若不足则补零;从"01"至"31" D: 星期几,3个英文字母,如:"Fri" F: 月份,英文全名,如:"January" h: 12小时制的小时,从"01"至"12" H: 24小时制的小时,从"00"至"23" g: 12小时制的小时,不补零;从"1"至"12" G: 24小时制的小时,不补零;从"0"至"23" j: 几日,不足不被零;从"1"至"31" l: 星期几,英文全名,如:"Friday" m: 月份,两位数字,从"01"至"12" n: 月份,两位数字,不补零;从"1"至"12" M: 月份,3个英文字母;如:"Jan" s: 秒;从"00"至"59" S: 字尾加英文序数,两个英文字母,如:"21th" t: 指定月份的天数,从"28"至"31" U: 总秒数 w: 数字型的星期几,从"0(星期天)"至"6(星期六)" Y: 年,四位数字 y: 年,两位数字 z: 一年中的第几天;从"1"至"366" ================================================================== 1,年-月-日 表示年可以用大写的Y和小写y; 表示月可以用大写F、大写M、小写m和小写n(分别表示字符和数字的两种方式); 表示日可以用小写d和小写j,大写S表示日期的后缀。 echo date('Y-m-j'); 2007-02-6 echo date('y-n-j'); 07-2-6 大写Y表示年四位数字,而小写y表示年的两位数字; 小写m表示月份的数字(带前导),而小写n则表示不带前导的月份数字。 echo date('Y-M-j'); 2007-Feb-6 echo date('Y-m-d'); 2007-02-06 大写M表示月份的3个缩写字符,而小写m则表示月份的数字(带前导0); 没有大写的J,只有小写j表示月份的日期,无前导o;若需要月份带前导则使用小写d。 echo date('Y-M-j'); 2007-Feb-6 echo date('Y-F-jS'); 2007-February-6th 大写M表示月份的3个缩写字符,而大写F表示月份的英文全写。(没有小写f) 大写S表示日期的后缀,比如“st”、“nd”、“rd”和“th”,具体看日期数字为何。 2,时:分:秒 默认情况下,PHP解释显示的时间为“格林威治标准时间”,与我们本地的时间相差8个小时。 echo date('g:i:s a'); 5:56:57 am echo date('h:i:s A'); 05:56:57 AM 小写g表示12小时制,无前导0,而小写h则表示有前导0的12小时制。 当使用12小时制时需要表明上下午,小写a表示小写的“am”和“pm”,大写A表示大写的“AM”和“PM”。 echo date('G:i:s'); 14:02:26 大写G表示24小时制的小时数,但是不带前导的;使用大写的H表示带前导的24小时制小时数 小结: 字母g表示小时不带前导,字母h表示小时带前导; 小写g、h表示12小时制,大写G、H表示24小时制。 3,闰年、星期、天 echo date('L'); 今年是否闰年:0 echo date('l'); 今天是:Tuesday echo date('D'); 今天是:Tue 大写L表示判断今年是否闰年,布尔值,为真返回1,否则为0; 小写l表示当天是星期几的英文全写(Tuesday); 而使用大写D表示星期几的3个字符缩写(Tue)。 echo date('w'); 今天星期:2 echo date('W'); 本周是全年中的第 06 周 小写w表示星期几,数字形式表示 大写W表示一年中的星期数 echo date('t'); 本月是 28 天 echo date('z'); 今天是今年的第 36 天 小写t表示当前月份又多少天 小写z表示今天是本年中第几天 4,其他 echo date('T'); UTC 大写T表示服务器的时间区域设置 echo date('I'); 大写I表示判断当前是否为夏令时,为真返回1,否则为0 echo date('U'); 大写U表示从1970年1月1日到现在的总秒数,就是Unix时间纪元的UNIX时间戳。 echo date('c'); 2007-02-06T14:24:43+00:00 小写c表示ISO8601日期,日期格式为YYYY-MM-DD,用字母T来间隔日期和时间,时间格式为HH:MM:SS,时区使用格林威治标准时间(GMT)的偏差来表示。 echo date('r'); Tue, 06 Feb 2007 14:25:52 +0000 小写r表示RFC822日期。 5、格式化时间 echo $row["t_time"]; 将输出 2008-2-29 12:08:00 echo date("Y-m-d",strtotime($row["t_time"])); 将输出 2008-2-29 注,由于$row["t_time"]得到的时间已经是一个字符串,所以需要用strtotime( 字串转时间戳)转一下,否则输出1970-01-01的错误to the front of the page
The above is the detailed content of Detailed explanation of php Date() function parameters. For more information, please follow other related articles on the PHP Chinese website!

In PHP, you can use session_status() or session_id() to check whether the session has started. 1) Use the session_status() function. If PHP_SESSION_ACTIVE is returned, the session has been started. 2) Use the session_id() function, if a non-empty string is returned, the session has been started. Both methods can effectively check the session state, and choosing which method to use depends on the PHP version and personal preferences.

Sessionsarevitalinwebapplications,especiallyfore-commerceplatforms.Theymaintainuserdataacrossrequests,crucialforshoppingcarts,authentication,andpersonalization.InFlask,sessionscanbeimplementedusingsimplecodetomanageuserloginsanddatapersistence.

Managing concurrent session access in PHP can be done by the following methods: 1. Use the database to store session data, 2. Use Redis or Memcached, 3. Implement a session locking strategy. These methods help ensure data consistency and improve concurrency performance.

PHPsessionshaveseverallimitations:1)Storageconstraintscanleadtoperformanceissues;2)Securityvulnerabilitieslikesessionfixationattacksexist;3)Scalabilityischallengingduetoserver-specificstorage;4)Sessionexpirationmanagementcanbeproblematic;5)Datapersis

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Dreamweaver CS6
Visual web development tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Atom editor mac version download
The most popular open source editor

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
