Remove select intervals and periods from the Edit Subscription page of Toolbox for WC Subscriptions

functions.php

<?php

/**
 * Modify the intervals offered by Toolbox for WC Subscriptions.
 *
 * @param array $intervals
 * @param WC_Subscription $subscription
 * @return mixed
 */
function sp_modify_intervals( $intervals, $subscription ) {
	// Remove 'every' if it is in the list.
	if ( ( $key = array_search( 'every', $intervals ) ) !== false ){
		unset( $intervals[$key] );
	}
	return $intervals;
}
add_filter( 'jgtb_change_intervals', 'sp_modify_intervals', 10, 2 );

/**
 * Modify the periods offered by Toolbox for WC Subscriptions
 * @param array $periods
 * @param WC_Subscription$subscription
 * @return mixed
 */
function sp_modify_periods( $periods, $subscription ) {
	// Remove 'day' if it is in the list.
	if ( ( $key = array_search( 'day', $periods ) ) !== false ){
		unset( $periods[$key] );
	}
	// Remove 'month' if it is in the list.
	if ( ( $key = array_search( 'month', $periods ) ) !== false ){
		unset( $periods[$key] );
	}
	// Remove 'year' if it is in the list.
	if ( ( $key = array_search( 'year', $periods ) ) !== false ){
		unset( $periods[$key] );
	}
	return $periods;
}
add_filter( 'jgtb_change_periods', 'sp_modify_periods', 10, 2 );

// Remove the 'Change Next Shipping Date' box from the Edit Subscription page
function sp_allow_edit_date(){
	return 'no';
}
add_filter('jgtb_allow_edit_date_for_subscription', 'sp_allow_edit_date', 10 );