Ever since installing version 2.x of dotProject, there has been a non-fatal error when creating a new task:

Warning: date() expects parameter 2 to be long, string given in /[...pathtodotproject...]/lib/PEAR/Date.php on line 179

Thanks to glynnsmith on the dotproject forums for coming up with a fix for the issue:

In /lib/PEAR/Date.php line 178-179 is:

            case DATE_FORMAT_UNIXTIME:

            $this->setDate(date("Y-m-d H:i:s", $date));

           break

case DATE_FORMAT_UNIXTIME:
if ($date != '') {
    $this->setDate(date("Y-m-d H:i:s", $date));
        }
else {
    $this->setDate(null);
    } 
break