Today is Friday, April 17, 2015. In my app, it automatically generated a "due date" for each assignment. It's set to "5 business days". To accomplish this, We use:
date('m/d/Y', strtotime("+5 weekdays"));
However, today, this output "04/26/2015". Why? That's a sunday. Why doesn't it give me the 24th, which is what I want?
DEMO: http://codepad.org/2wvnypOC
P.S. After speaking to my boss, we switched to strtotime("+5 days"), but I'm still curious what was wrong with "weekdays".
It's a bug.
It has been fixed in >= 5.5.0.
So you'll need to work around it or upgrade your php version.
<?php
$today = strtotime('2015-04-17 00:00:00');
echo date('m/d/Y', strtotime("+5 weekdays", $today));
echo "\n";
echo phpversion( );
?>
来源：https://stackoverflow.com/questions/29707554/php-strtotime-incrementing-by-weekdays