Jason ... this is totally weird. I moved the line of code you asked me to add from line 1 of the update page to line 4 and it's working now without any errors.
<?php require_once("webassist/form_validations/wavt_scripts_php.php"); ?>
<?php require_once("webassist/form_validations/wavt_validatedform_php.php"); ?>
<?php require_once('Connections/timesheets.php'); ?>
<?php if(isset($_POST["dateWorked"])) $_POST["dateWorked"] = date("Y-m-d",strtotime($_POST["dateWorked"])); ?>