此函数是该函数的别名： DateTime::sub()
Jonathan Poissant (2011-01-21 07:26:02)
You cannot replace date_sub('2000-01-20') by DateTime::sub('2000-01-20') because DateTime::sub is not static. You have to create the DateTime object first.
Example:
<?php $dateA = date_sub('2000-01-20', date_interval_create_from_date_string('10 days')); ?>
will be replace by
<?php
$dateB = new DateTime('2000-01-20');
$dateA = $dateB->sub(date_interval_create_from_date_string('10 days'));
?>