a slightly more compact way of getting the month shift
<?php
/**
* correctly calculates end of months when we shift to a shorter or longer month
* workaround for http://php.net/manual/en/datetime.add.php#example-2489
*
* Makes the assumption that shifting from the 28th Feb +1 month is 31st March
* Makes the assumption that shifting from the 28th Feb -1 month is 31st Jan
* Makes the assumption that shifting from the 29,30,31 Jan +1 month is 28th (or 29th) Feb
*
*
* @param DateTime $aDate
* @param int $months positive or negative
*
* @return DateTime new instance - original parameter is unchanged
*/
function MonthShifter (DateTime $aDate,$months){
$dateA = clone($aDate);
$dateB = clone($aDate);
$plusMonths = clone($dateA->modify($months . ' Month'));
//check whether reversing the month addition gives us the original day back
if($dateB != $dateA->modify($months*-1 . ' Month')){
$result = $plusMonths->modify('last day of last month');
} elseif($aDate == $dateB->modify('last day of this month')){
$result = $plusMonths->modify('last day of this month');
} else {
$result = $plusMonths;
}
return $result;
}
//TEST
$x = new DateTime('2017-01-30');
echo( $x->format('Y-m-d')." past end of feb, but not dec<br>");
echo('b ' . MonthShifter($x,1)->format(('Y-m-d'))."<br>");
echo('c ' . MonthShifter($x,-1)->format(('Y-m-d'))."<br>");
$x = new DateTime('2017-01-15');
echo("<br>" . $x->format('Y-m-d')." middle of the month <br>");
echo('d ' . MonthShifter($x,1)->format(('Y-m-d'))."<br>");
echo('e ' . MonthShifter($x,-1)->format(('Y-m-d'))."<br>");
$x = new DateTime('2017-02-28');
echo("<br>" . $x->format('Y-m-d')." end of Feb<br>");
echo('f ' . MonthShifter($x,1)->format(('Y-m-d'))."<br>");
echo('g ' . MonthShifter($x,-1)->format(('Y-m-d'))."<br>");
$x = new DateTime('2017-01-31');
echo("<br>" . $x->format('Y-m-d')." end of Jan<br>");
echo('h ' . MonthShifter($x,1)->format(('Y-m-d'))."<br>");
echo('i ' . MonthShifter($x,-1)->format(('Y-m-d'))."<br>");
$x = new DateTime('2017-01-31');
echo("<br>" . $x->format('Y-m-d')." end of Jan +/- 1 years diff, leap year respected<br>");
echo('j ' . MonthShifter($x,13)->format(('Y-m-d'))."<br>");
echo('k ' . MonthShifter($x,-11)->format(('Y-m-d'))."<br>");
//returns
2017-01-30 past end of feb, but not dec
b 2017-02-28
c 2016-12-30
2017-01-15 middle of the month
d 2017-02-15
e 2016-12-15
2017-02-28end of Feb
f 2017-03-31
g 2017-01-31
2017-01-31end of Jan
h 2017-02-28
i 2016-12-31
2017-01-31end of Jan +/- 1 years diff, leap year respected
j 2018-02-28
k 2016-02-29
PHP - Manual: DateTime::modify
2024-12-21
DateTime::modify
date_modify
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
DateTime::modify -- date_modify — 修改日期时间对象的值
参数
-
object -
仅过程化风格：由 date_create() 返回的 DateTime 类型的对象。此函数会修改这个对象。
-
modifier -
日期/时间字符串。正确格式的说明详见 日期与时间格式。
返回值
返回被修改的 DateTime 对象， 或者在失败时返回 false.
范例
示例 #1 DateTime::modify() 例程
面向对象风格
<?php
$date = new DateTime('2006-12-12');
$date->modify('+1 day');
echo $date->format('Y-m-d');
?>
过程化风格
<?php
$date = date_create('2006-12-12');
date_modify($date, '+1 day');
echo date_format($date, 'Y-m-d');
?>
以上例程会输出：
2006-12-13
示例 #2 增加或者减少月份的时候需要注意
<?php
$date = new DateTime('2000-12-31');
$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";
$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";
?>
以上例程会输出：
2001-01-31 2001-03-03
参见
- strtotime() - 将任何字符串的日期时间描述解析为 Unix 时间戳
- DateTime::add() - 给一个 DateTime 对象增加一定量的天，月，年，小时，分钟 以及秒。
- DateTime::sub() - 对一个 DateTime 对象减去一定量的 日、月、年、小时、分钟和秒。
- DateTime::setDate() - 设置 DateTime 对象的日期
- DateTime::setISODate() - 设置 ISO 日期
- DateTime::setTime() - 设置 DateTime 对象的时间
- DateTime::setTimestamp() - 以 Unix 时间戳的方式设置 DateTime 对象
add a note
User Contributed Notes 15 notes
mangotonk at gmail dot com ¶
5 years ago
jenspj at msn dot com ¶
10 years ago
These functions makes sure that adding months or years always ends up in the month you would expect. Works for positive and negative values
<?php
$date=new DateTime();
$date->setDate(2008,2,29);
function addMonths($date,$months){
$init=clone $date;
$modifier=$months.' months';
$back_modifier =-$months.' months';
$date->modify($modifier);
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
while($init->format('m')!=$back_to_init->format('m')){
$date->modify('-1 day') ;
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
}
/*
if($months<0&&$date->format('m')>$init->format('m'))
while($date->format('m')-12-$init->format('m')!=$months%12)
$date->modify('-1 day');
else
if($months>0&&$date->format('m')<$init->format('m'))
while($date->format('m')+12-$init->format('m')!=$months%12)
$date->modify('-1 day');
else
while($date->format('m')-$init->format('m')!=$months%12)
$date->modify('-1 day');
*/
}
function addYears($date,$years){
$init=clone $date;
$modifier=$years.' years';
$date->modify($modifier);
while($date->format('m')!=$init->format('m'))
$date->modify('-1 day');
}
addMonths($date,-1);
addYears($date,3);
echo $date->format('F j,Y');
?>
www dot wesley at gmail dot com ¶
6 years ago
This is an improvement of @jenspj's answer
<?php
$d = new DateTime('2007-12-31');
function addMonths($date, $months)
{
$years = floor(abs($months / 12));
$leap = 29 <= $date->format('d');
$m = 12 * (0 <= $months?1:-1);
for ($a = 1;$a < $years;++$a) {
$date = addMonths($date, $m);
}
$months -= ($a - 1) * $m;
$init = clone $date;
if (0 != $months) {
$modifier = $months . ' months';
$date->modify($modifier);
if ($date->format('m') % 12 != (12 + $months + $init->format('m')) % 12) {
$day = $date->format('d');
$init->modify("-{$day} days");
}
$init->modify($modifier);
}
$y = $init->format('Y');
if ($leap && ($y % 4) == 0 && ($y % 100) != 0 && 28 == $init->format('d')) {
$init->modify('+1 day');
}
return $init;
}
function addYears($date, $years)
{
return addMonths($date, 12 * $years);
}
echo $d->format('F j,Y') . ' N<br />';
$d = addMonths($d, +1);
echo $d->format('F j,Y') . ' +1M<br />';
$d = addMonths($d, +1);
echo $d->format('F j,Y') . ' +1M<br />';
$d = addYears($d, +60);
echo $d->format('F j,Y') . ' +60Y<br />';
$d = addYears($d, -59);
echo $d->format('F j,Y') . ' -59Y<br />';
jay dot removethis at grooveshark dot com ¶
8 years ago
Due to DST and the way DateTime internally handles dates, it's possible to get stuck in a time loop.
For example:
<?php
$dt = new DateTime('2012-03-11 3:00AM');
echo $dt->format('YmdH') . "\n";
$dt->modify("-1 hour");
echo $dt->format('YmdH') . "\n";
$dt->modify("-1 hour");
echo $dt->format('YmdH') . "\n";
?>
prints out:
2012031103
2012031103
2012031103
if your timezone is set to America/New_York.
66Ton99 ¶
8 years ago
Extension for DateTime class which solves problem of adding or subtracting months
https://gist.github.com/66Ton99/60571ee49bf1906aaa1c
Jenny jsimonds@atomic jet packs dot com ¶
10 years ago
Note: This method modifies the object in-place. So if you want to calculate a new date but assign the new value to a different object, this will NOT work:
<?php
$numMinutes = 25;
$oDateA = new DateTime('2012-01-01 12:00:00');
print "
Original:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
";
$oDateB = $oDateA->modify ("+{$numMinutes} minutes");
print "
plus {$numMinutes} minutes:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
oDateB = {$oDateB->format('Y-m-d H-i-s')}<br>
";
?>
...produces this:
oDateA = 2012-01-01 12-00-00
plus 25 minutes:
oDateA = 2012-01-01 12-25-00
oDateB = 2012-01-01 12-25-00
Use something like this instead:
<?php
$numMinutes = 25;
$oDateA = new DateTime('2012-01-01 12:00:00');
print "
<p>
Original:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
";
$oDateB = clone $oDateA;
$oDateB->modify ("+{$numMinutes} minutes");
print "
plus {$numMinutes} minutes:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
oDateB = {$oDateB->format('Y-m-d H-i-s')}<br>
";
?>
... produces this:
oDateA = 2012-01-01 12-00-00
plus 25 minutes:
oDateA = 2012-01-01 12-00-00
oDateB = 2012-01-01 12-25-00
hienle ¶
2 months ago
Keep in mind that method chaining is only available from PHP 5.3, so with older versions, this will not work:
<?php
$exp_date = new DateTime();
echo $exp_date->modify("-10 month")->format("Y-m-d");
?>
This will work:
<?php
$exp_date = new DateTime();
$exp_date->modify("-10 month");
echo $exp_date->format("Y-m-d");
?>
wes at anonymous dot com ¶
1 year ago
Beware, the modify function does not treat .5 as a half minute!
echo "start with: $str\n";
$datetimeObj = new DateTime($str);
$datetimeObj->modify('1 minutes');
echo "add 1 min: ".$datetimeObj->format('m/d/Y h:i:s A')."\n";
$datetimeObj = new DateTime($str);
$datetimeObj->modify('.5 minutes');
echo "add .5 min: ".$datetimeObj->format('m/d/Y h:i:s A')."\n";
$datetimeObj->modify('.53453531 minutes');
echo "add .53453531 min: ".$datetimeObj->format('m/d/Y h:i:s A')."\n";
start with: 05/25/2021 02:53:40 PM
add 1 min: 05/25/2021 02:54:40 PM
add .5 min: 05/25/2021 02:58:40 PM
add .53453531 min: 01/12/2123 03:09:40 AM
.5 minutes actually ends up adding 5 minutes, not a half minute, and .53453531 adds 53453531 minutes.
So, if you have a function that accepts a number for adding minutes to a datetime, you have to check for < 1 and > -1, and then possibly convert that to seconds and do a seconds modification.
sg@rg ¶
2 years ago
Made a different fixed version using the month not the day
<?php
function modifyMonth(DateTime $date, string $modificator): DateTime {
$destMonth = $date->format('m') + $date->format('Y') * 12 + ($modificator);
$date->modify("$modificator months");
while ($date->format('m') + $date->format('Y') * 12 > $destMonth)
$date->modify('-1 day');
return $date;
}
?>
Testing :
<?php
$dates = [
['2020/02/29', '+1', '2020/03/29'],
['2020/02/29 12:34', '-1', '2020/01/29 12:34'],
['2020/03/29 01:01', '+1', '2020/04/29 01:01'],
['2020/03/29', '-1', '2020/02/29'],
['2020/03/30', '+1', '2020/04/30'],
['2020/03/30 23:58', '-1', '2020/02/29 23:58'],
['2020/03/31', '+1', '2020/04/30'],
['2020/03/31', '-1', '2020/02/29'],
['2020/03/31', '+2', '2020/05/31'],
['2020/03/31 00:01', '-2', '2020/01/31 00:01'],
['2020/03/01', '+1', '2020/04/01'],
['2020/03/01', '-1', '2020/02/01'],
['2020/02/01', '+1', '2020/03/01'],
['2020/02/01', '-1', '2020/01/01'],
['2020/04/01', '+1', '2020/05/01'],
['2020/04/01 22:22', '-1', '2020/03/01 22:22'],
['2020/12/31', '+2', '2021/02/28'],
['2020/01/31', '-2', '2019/11/30'],
];
foreach ($dates as $date) {
$test = new DateTime($date[0]);
modifyMonth($test, $date[1]);
if ($test != new DateTime($date[2]))
echo $date[0] . " " . $date[1] . " != " . $test->format('c') . "\n";
}
?>
Testing prints no error
widowmaker at example dot com ¶
2 years ago
date_default_timezone_set('Europe/Amsterdam');
$dt = new DateTime('27 October 2019 00:20:00');
print_r($dt);
$dt->modify('600 min');
print_r($dt);
$dt = new DateTime('27 October 2019 00:20:00');
$dt->add(date_interval_create_from_date_string('600 min'));
print_r($dt);
// produces
DateTime Object
(
[date] => 2019-10-27 00:20:00.000000
[timezone_type] => 3
[timezone] => Europe/Amsterdam
)
DateTime Object
(
[date] => 2019-10-27 10:20:00.000000
[timezone_type] => 3
[timezone] => Europe/Amsterdam
)
DateTime Object
(
[date] => 2019-10-27 09:20:00.000000
[timezone_type] => 3
[timezone] => Europe/Amsterdam
)
ilyaplot at gmail dot com ¶
4 years ago
function subMonths(\Datetime $dateTime, int $months)
{
if ($invert = $months < 0) {
$months *= -1;
}
for ($i=0; $i<$months; $i++) {
$daysOfMonth = cal_days_in_month(CAL_GREGORIAN, $dateTime->format('m'), $dateTime->format('Y'));
$dateTime->modify(($invert ? '-' : '+') . $daysOfMonth . ' day');
}
return $dateTime;
}
$dateTime = new \DateTime('2004-12-31');
echo $dateTime->modify('-3 month')->format('Y-m-d'); // 2004-10-01
echo subMonths($dateTime, -3)->format('Y-m-d'); // 2004-09-30
sinus at sinpi dot net ¶
5 years ago
A very simple way to ensure we do not cross over month boundaries when adding months is to just go back a few days if the day number got reset:
<?php
function addMonths($date,$months) {
$orig_day = $date->format("d");
$date->modify("+".$months." months");
while ($date->format("d")<$orig_day && $date->format("d")<5) {
$date->modify("-1 day");
}
}
for ($i=0;$i<5;$i++) {
$d = new DateTime("2000-01-10");
addmonths($d,$i);
echo $d->format("Y-m-d")."<br>";
}
for ($i=0;$i<5;$i++) {
$d = new DateTime("2000-01-31");
addmonths($d,$i);
echo $d->format("Y-m-d")."<br>";
}
?>
prints:
2000-01-10
2000-02-10
2000-03-10
2000-04-10
2000-05-10
2000-01-31
2000-02-29
2000-03-31
2000-04-30
2000-05-31
admin at wmfoi dot com dot br ¶
8 years ago
The changelog says: "5.3.0 - Changed the return value on success from NULL to DateTime".
That means that you can't do a Fluid Interface design with it in PHP 5.2.
In other words, this will not work in 5.2:
<?php
$DateTime=new DateTime();
echo $DateTime->modify('+1 day')->format('d');
?>
php at lanar dot com dot au ¶
8 years ago
modify() ignores any timezone information in the data while the DateTime constructor does not.
$dt = new DateTime( '2013-10-26T11:00:00+11:00' )
will create a +11 timezone while
$dt->modify( '2013-10-26T11:00:00+02:00' )
does not change the timezone or the time.
<?php
$dt = new DateTime( '2013-10-26T15:00:00Australia/Melbourne' ) ;
echo "\n", $dt->format( "c" ) ;
echo "\nTimezone '", $dt->getTimezone()->getName() . "'." ;
// modify $dt to 1 am new york which is 3 pm melbourne
$dt->modify( '2013-10-26T01:00:00America/New_York' ) ;
// result is 1 am melbourne time, not 3 pm
echo "\n", $dt->format( "c" ) ;
echo "\nTimezone '", $dt->getTimezone()->getName() . "'." ;
?>
Output
2013-10-26T15:00:00+11:00
Timezone 'Australia/Melbourne'.
2013-10-26T01:00:00+11:00
Timezone 'Australia/Melbourne'.
vittorio dot zamparella at gmail dot com ¶
3 years ago
@Anonimous
There is no bug. Especially not any retarded one.
<?
function plusOneMonthTests($dateString, $expectation) {
$date = new DateTime($dateString);
echo "[".$date->format('Y-m-d')."] +1 month = [".$date->modify('+1 month')->format('Y-m-d')."] $expectation \n";
}
plusOneMonthTests('2001-01-01', 'as expected');
plusOneMonthTests('2001-01-27', 'as expected');
plusOneMonthTests('2001-01-28', 'as expected');
plusOneMonthTests('2001-01-29', 'what would you expect?');
plusOneMonthTests('2001-01-30', 'what would you expect?');
plusOneMonthTests('2001-01-31', 'what would you expect?');
?>
Result:
[2001-01-01] +1 month = [2001-02-01] as expected
[2001-01-27] +1 month = [2001-02-27] as expected
[2001-01-28] +1 month = [2001-02-28] as expected
[2001-01-29] +1 month = [2001-03-01] what would you expect? 29 of february??
[2001-01-30] +1 month = [2001-03-02] what would you expect? or 30 of february?
[2001-01-31] +1 month = [2001-03-03] what would you expect?
As with any tool you need to know how to use it.
I think most people are looking for "the same day of the next month" (or any other number or months).
The calendar is twisted, don't blame the library.
IT
PHP
编程语言
Linux
开发编程
科技
Elasticsearch
HTML/CSS/XML
网络
数据库
JAVA
面试
NoSQL
C/C++
Golang
Git
算法
操作系统
正则表达式
Redis
互联网
MySql
JavaScript
运维
软件
国际
架构设计
Mac OS
TCP/IP
Excel
Vim
Windows
Socket
Oracle
VR
MongoDB
Python
运营
MemCache
商业
硬件
电子
娱乐
设计
nginx
摄影
游戏
WordPress
HTTP
团建
数码电器
广告
广告
php7 安装fileinfo扩展
preg_split — 通过一个正则表达式分隔字符串
php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题
[PHP] inet_pton/inet_ntop IP地址转换函数
PHP 8.1
[鸟哥]PHP_INT_MIN 和 -9223372036854775808
adodb手册
ADORecordSet对象
opcache预加载
Composer的Packagist资源
array_multisort() 多字段排序
PHPMailer设置utf8 PHPMailer字符集CharSet
mysql面试题
PHP json解析（json_decode）页面工具
php中几种注释规范
纯php实现DES以及TripleDES加密算法
php 修改图片大小
支持php7的性能采集扩展
[原创]诡异的php-fpm超时问题
两千行PHP学习笔记