您可以将它们转换为时间戳，

  $ hourdiff = round（（strtotime（$ time1） -  strtotime（$ time2））/ 3600，1）; 
 

除以3600，因为一小时内有3600秒，使用 round ）以避免有很多小数位。

I have two dates, formated like "Y-m-d H:i:s". I need to compare these two dates and figure out the hour difference.

You can convert them to timestamps and go from there:

$hourdiff = round((strtotime($time1) - strtotime($time2))/3600, 1);

Dividing by 3600 because there are 3600 seconds in one hour and using round() to avoid having a lot of decimal places.