I'm trying to upgrade an app from PHP 5.4 to PHP 5.6 or 7 on Windows/IIS. Things seem to work fine for the most part, the one difference that's causing some problems when converting values is that DateTime object's string default string representation is something like 2016-03-24 14:34:22.000000 in PHP 5.6 and 7, whereas in PHP 5.4 it was 2016-03-24 14:34:22. To test, all you have to do is var_dump(new DateTime()); and you'll see the value of the "date" key.
I've searched quite a bit and am not finding anything at all in regards to this change. Is there any setting that can be used to revert the format to the way it was in 5.4?