(PHP 5 >= 5.3.0)
DateTime::add — Adds an amount of days, months, years, hours, minutes and seconds to a DateTime object
Adds the specified DateInterval object to the specified DateTime object.
Procedural style only: A DateTime object returned by date_create()
The amount to be added. For the date use "P3D", "P3M", "P3Y" or a combination of the three e.g. "P2M5D" (Y = Years, M = Months, D = Days.) MUST BE YEAR MONTH DAY FORMAT "P5Y", "P5M2D", "P5Y4D". For the time use "T3H", "T3M", "T3S" or or a combination of the three e.g. "T5H20M" (H = Hours, M = Minutes, S = Seconds). For dateTime use "P5D2M4YT5H20M". The digit before the letter (NOT P or T) can be any amount.
Returns the modified DateTime.
Example #1 date_add() example
<?php
$date = new DateTime("18-July-2008 16:30:30");
echo $date->format("d-m-Y H:i:s").'<br />';
date_add($date, new DateInterval("P5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days';
date_add($date, new DateInterval("P5M"));
echo '<br />'.$date->format("d-m-Y").' : 5 Months';
date_add($date, new DateInterval("P5Y"));
echo '<br />'.$date->format("d-m-Y").' : 5 Years';
date_add($date, new DateInterval("P5Y5M5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days, 5 Months, 5 Years';
date_add($date, new DateInterval("P5YT5H"));
echo '<br />'.$date->format("d-m-Y H:i:s").' : 5 Years, 5 Hours';
?>
本函数是实验性的。本函数的行为，包括函数名称以及其它任何关于本函数的文档可能会在没有通知的情况下随 PHP 以后的发布而改变。使用本函数风险自担。