Gravity Forms - UNIX Timestamp

gistfile1.aw

<?php

add_action( 'gform_post_submission_1', 'be_event_timestamp', 10, 2 );
/**
 * Create a UNIX timestamp based on Gform date fields
 * @author Bill Erickson
 * @link http://www.billerickson.net/code/gravity-forms-unix-timestamp
 * @link http://www.gravityhelp.com/documentation/page/Gform_post_submission
 *
 * 'gform_post_submission' applies to all forms, append form ID to specify
 *
 * @param array $entry
 * @param array $form
 * @return array
 */
function be_event_timestamp( $entry, $form ) {
	$start_date = get_post_meta( $entry['post_id'], 'be_event_start_date', true );
	if( $start_date ) {
		$timestamp = strtotime( $start_date );
		update_post_meta( $entry['post_id'], 'be_event_start_date_unix', $timestamp );		
	}
	
	$end_date = get_post_meta( $entry['post_id'], 'be_event_end_date', true );
	if( $end_date ) {
		$timestamp = strtotime( $end_date );
		update_post_meta( $entry['post_id'], 'be_event_end_date_unix', $timestamp );
	}
}