Subtracting dates in PHP [duplicate]

问题:

Possible Duplicate:
How to calculate the difference between two dates using PHP?

I have timestamps stored in the format YYYY-MM-DD HH:MM:SS (for example 2010-06-21 20:12:56). What would the best way to check how old the timestamp is? For the moment I am mainly interested in the number of days old.

回答1:

You can use strtotime to convert the string to a UNIX timestamp, which is in seconds. time() will give you the current UNIX timestamp. Subtract them to get how old the date is in seconds, and divide by 60*60*24 to get it in days

It's also doable using DateTime::diff, although I find the date functions easier than using the classes

回答2:

$today = strtotime(date('Y-m-d H:i:s'));
$expireDay = strtotime($row['ExpireDate']);
$timeToEnd = $expireDay - $today;