(PHP 5 >= 5.3.0, PHP 7)
DateTime::add -- date_add — 锟斤拷一锟斤拷 DateTime 锟斤拷锟斤拷锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷锟届，锟铰ｏ拷锟疥，小时锟斤拷锟斤拷锟斤拷 锟皆硷拷锟诫。
object锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟� date_create() 锟斤拷锟截碉拷 DateTime 锟斤拷锟酵的讹拷锟襟。此猴拷锟斤拷锟斤拷锟睫革拷锟斤拷锟斤拷锟斤拷锟�
interval
DateInterval 锟斤拷锟斤拷
锟斤拷锟截憋拷锟睫改碉拷 DateTime 锟斤拷锟斤拷 锟斤拷锟斤拷锟斤拷失锟斤拷时锟斤拷锟斤拷 FALSE.
Example #1 DateTime::add() 锟斤拷锟斤拷
锟斤拷锟斤拷锟斤拷锟斤拷锟�
<?php
$date = new DateTime('2000-01-01');
$date->add(new DateInterval('P10D'));
echo $date->format('Y-m-d') . "\n";
?>
锟斤拷锟教伙拷锟斤拷锟�
<?php
$date = date_create('2000-01-01');
date_add($date, date_interval_create_from_date_string('10 days'));
echo date_format($date, 'Y-m-d');
?>
锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�
2000-01-11
Example #2 Further DateTime::add() 锟斤拷锟斤拷
<?php
$date = new DateTime('2000-01-01');
$date->add(new DateInterval('PT10H30S'));
echo $date->format('Y-m-d H:i:s') . "\n";
$date = new DateTime('2000-01-01');
$date->add(new DateInterval('P7Y5M4DT4H3M2S'));
echo $date->format('Y-m-d H:i:s') . "\n";
?>
锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�
2000-01-01 10:00:30 2007-06-05 04:03:02
Example #3 锟斤拷锟斤拷 DateTime 锟较硷拷锟铰碉拷时锟斤拷要注锟斤拷
<?php
$date = new DateTime('2000-12-31');
$interval = new DateInterval('P1M');
$date->add($interval);
echo $date->format('Y-m-d') . "\n";
$date->add($interval);
echo $date->format('Y-m-d') . "\n";
?>
锟斤拷锟斤拷锟斤拷锟教伙拷锟斤拷锟斤拷锟�
2001-01-31 2001-03-03
锟斤拷 PHP 5.2 锟侥版本锟叫ｏ拷 也锟斤拷锟斤拷使锟斤拷 DateTime::modify() 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�