Hi,
in previous script I see something like:

$userRow['gebdatum']= date('Y-m-d',strtotime($userRow['geburtsdatum']));

"strtotime" return UNIX timestamp based on server timezone (probably Universal Time Coordinates UTC)
"date" return formatted date based on application timezone (I think)

Still, i found a problem with import plugin and latest release of Easy Profile, now in import file is accepted date value like parameter "Form Date Format - Edit Profile/Registration" in date field options (see screenshot), this is wrong, correct should be YYYY-MM-DD. So now if it works for you it's ok, but from next release of Easy Profile you should use correct format in CSV file (or in your php code)