function wp_unschedule_hook( $hook ) {
	/**
	 * Filter to preflight or hijack clearing all events attached to the hook.
	 *
	 * Returning a non-null value will short-circuit the normal unscheduling
	 * process, causing the function to return the filtered value instead.
	 *
	 * For plugins replacing wp-cron, return the number of events successfully
	 * unscheduled (zero if no events were registered with the hook) or false
	 * if unscheduling one or more events fails.
	 *
	 * @since 5.1.0
	 *
	 * @param null|int|false $pre  Value to return instead. Default null to continue unscheduling the hook.
	 * @param string         $hook Action hook, the execution of which will be unscheduled.
	 */
	$pre = apply_filters( 'pre_unschedule_hook', null, $hook );
	if ( null !== $pre ) {
		return $pre;
	}

	$crons = _get_cron_array();
	if ( empty( $crons ) ) {
		return 0;
	}

	$results = array();
	foreach ( $crons as $timestamp => $args ) {
		if ( ! empty( $crons[ $timestamp ][ $hook ] ) ) {
			$results[] = count( $crons[ $timestamp ][ $hook ] );
		}
		unset( $crons[ $timestamp ][ $hook ] );

		if ( empty( $crons[ $timestamp ] ) ) {
			unset( $crons[ $timestamp ] );
		}
	}

	/*
	 * If the results are empty (zero events to unschedule), no attempt
	 * to update the cron array is required.
	 */
	if ( empty( $results ) ) {
		return 0;
	}
	if ( _set_cron_array( $crons ) ) {
		return array_sum( $results );
	}
	return false;
}