Subtracting days from dates in PHP can be achieved by strtotime() and DateTime classes. Use strtotime() to operate directly through strings, such as date("Ymd", strtotime("-3 days", strtotime($date))); the recommended DateTime class is clearer and maintainable, supporting time zones and complex logic, such as $date->modify("-3 days") or $date->sub(new DateInterval('P3D')). Notes include: setting time zones to avoid deviations, ensuring that the date format is valid, and handling illegal date problems caused by negative values.
In PHP, if you need to subtract a few days from a date, there are several ways to do so. PHP provides flexible date handling functions, such as date() , strtotime() and DateTime classes, which can be used to complete this task.
Use strtotime() to subtract the number of days
This is one of the easiest and straightforward methods, suitable for most basic scenarios.
$date = "2025-04-05";
$newDate = date("Ymd", strtotime("-3 days", strtotime($date)));
echo $newDate; // Output 2025-04-02 The meaning of this code is: push forward 3 days from April 5, 2025.
Note : strtotime() is more sensitive to formats, and it is recommended to use standard date formats (such as Ymd) to avoid parsing errors.
Common usages include:
-
-1 day -
-7 days - It can even be written into natural language expressions such as
last Monday.
Use the DateTime class to operate (recommended)
If you want the code to be clearer and more maintainable, especially when it comes to complex time logic, it is recommended to use DateTime class.
$date = new DateTime("2025-04-05");
$date->modify("-3 days");
echo $date->format("Ymd"); // Output 2025-04-02The advantages of this method are:
- More object-oriented and clear structure
- Support time zone settings
- More complex rules can be used in combination with
DateInterval
For example, use DateInterval :
$date = new DateTime("2025-04-05");
$date->sub(new DateInterval('P3D')); // P represents the time period, 3D represents 3 days echo $date->format("Ymd");Notes and FAQs
Some small details are easily overlooked, but they will affect the results:
- Time zone problem : If the time zone is not explicitly set in the script, it may cause output bias. You can use
date_default_timezone_set()to set. - Invalid date format : Some non-standard formats may cause
strtotime()to fail parsing. - Negative value processing : After subtracting the number of days, do not forget to check whether it becomes an illegal date (for example, 2025-02-28 Subtracting 3 days will reach February 25, no problem; but if the original date is 0000-01-01, an error may occur).
Basically these methods. You can select strtotime() or DateTime class according to the complexity of the project to implement the "subtract days" function in PHP. Both methods can meet the needs, but the latter is more suitable for long-term maintenance and expansion.
The above is the detailed content of php subtract days from date. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
What are some best practices for versioning a PHP-based API?
Jun 14, 2025 am 12:27 AM
ToversionaPHP-basedAPIeffectively,useURL-basedversioningforclarityandeaseofrouting,separateversionedcodetoavoidconflicts,deprecateoldversionswithclearcommunication,andconsidercustomheadersonlywhennecessary.StartbyplacingtheversionintheURL(e.g.,/api/v
How do I implement authentication and authorization in PHP?
Jun 20, 2025 am 01:03 AM
TosecurelyhandleauthenticationandauthorizationinPHP,followthesesteps:1.Alwayshashpasswordswithpassword_hash()andverifyusingpassword_verify(),usepreparedstatementstopreventSQLinjection,andstoreuserdatain$_SESSIONafterlogin.2.Implementrole-basedaccessc
What are the differences between procedural and object-oriented programming paradigms in PHP?
Jun 14, 2025 am 12:25 AM
Proceduralandobject-orientedprogramming(OOP)inPHPdiffersignificantlyinstructure,reusability,anddatahandling.1.Proceduralprogrammingusesfunctionsorganizedsequentially,suitableforsmallscripts.2.OOPorganizescodeintoclassesandobjects,modelingreal-worlden
What are weak references (WeakMap) in PHP, and when might they be useful?
Jun 14, 2025 am 12:25 AM
PHPdoesnothaveabuilt-inWeakMapbutoffersWeakReferenceforsimilarfunctionality.1.WeakReferenceallowsholdingreferenceswithoutpreventinggarbagecollection.2.Itisusefulforcaching,eventlisteners,andmetadatawithoutaffectingobjectlifecycles.3.YoucansimulateaWe
How can you handle file uploads securely in PHP?
Jun 19, 2025 am 01:05 AM
To safely handle file uploads in PHP, the core is to verify file types, rename files, and restrict permissions. 1. Use finfo_file() to check the real MIME type, and only specific types such as image/jpeg are allowed; 2. Use uniqid() to generate random file names and store them in non-Web root directory; 3. Limit file size through php.ini and HTML forms, and set directory permissions to 0755; 4. Use ClamAV to scan malware to enhance security. These steps effectively prevent security vulnerabilities and ensure that the file upload process is safe and reliable.
What are the differences between == (loose comparison) and === (strict comparison) in PHP?
Jun 19, 2025 am 01:07 AM
In PHP, the main difference between == and == is the strictness of type checking. ==Type conversion will be performed before comparison, for example, 5=="5" returns true, and ===Request that the value and type are the same before true will be returned, for example, 5==="5" returns false. In usage scenarios, === is more secure and should be used first, and == is only used when type conversion is required.
How can you interact with NoSQL databases (e.g., MongoDB, Redis) from PHP?
Jun 19, 2025 am 01:07 AM
Yes, PHP can interact with NoSQL databases like MongoDB and Redis through specific extensions or libraries. First, use the MongoDBPHP driver (installed through PECL or Composer) to create client instances and operate databases and collections, supporting insertion, query, aggregation and other operations; second, use the Predis library or phpredis extension to connect to Redis, perform key-value settings and acquisitions, and recommend phpredis for high-performance scenarios, while Predis is convenient for rapid deployment; both are suitable for production environments and are well-documented.
How do I perform arithmetic operations in PHP ( , -, *, /, %)?
Jun 19, 2025 pm 05:13 PM
The methods of using basic mathematical operations in PHP are as follows: 1. Addition signs support integers and floating-point numbers, and can also be used for variables. String numbers will be automatically converted but not recommended to dependencies; 2. Subtraction signs use - signs, variables are the same, and type conversion is also applicable; 3. Multiplication signs use * signs, which are suitable for numbers and similar strings; 4. Division uses / signs, which need to avoid dividing by zero, and note that the result may be floating-point numbers; 5. Taking the modulus signs can be used to judge odd and even numbers, and when processing negative numbers, the remainder signs are consistent with the dividend. The key to using these operators correctly is to ensure that the data types are clear and the boundary situation is handled well.
