Ninja Forms Timestamp

gistfile1.php

<?php
/*
Plugin Name: Example Plugin
*/
<?php
function my_ninja_forms_date_code(){
  //Declare $ninja_forms_processing as a global variable.
  global $ninja_forms_processing;
  //only process this code on the form ID 1
  $form_id = $ninja_forms_processing->get_form_ID();
  if( $form_id == 1 ){
    //sets timestamp variable to current time
    $timestamp = date('h:i:s A');
        //Update the hidden field value for the field with an ID of 3 to the current time.
    $ninja_forms_processing->update_field_value( 3, $timestamp );
  }
}

add_action( 'ninja_forms_process', 'my_ninja_forms_date_code' );

Thanks - this works well. How does one add a timezone instead of defaulting to UTC?