subscription-periods-filter.php

<?php

/**
 * Add $number param to woocommerce-subscriptions.
 *
 * @param int (optional) An interval in the range 1-6
 * @param string (optional) One of day, week, month or year. If empty, all subscription ranges are returned.
 * @since 2.0
 */
function wcs_get_subscription_period_strings( $number = 1, $period = '' ) {
	$translated_periods = apply_filters( 'woocommerce_subscription_periods',
		array(
			// translators: placeholder is number of days. (e.g. "Bill this every day / 4 days")
			'day'   => sprintf( _nx( 'day',   '%s days',   $number, 'Subscription billing period.', 'woocommerce-subscriptions' ), $number ),
			// translators: placeholder is number of weeks. (e.g. "Bill this every week / 4 weeks")
			'week'  => sprintf( _nx( 'week',  '%s weeks',  $number, 'Subscription billing period.', 'woocommerce-subscriptions' ), $number ),
			// translators: placeholder is number of months. (e.g. "Bill this every month / 4 months")
			'month' => sprintf( _nx( 'month', '%s months', $number, 'Subscription billing period.', 'woocommerce-subscriptions' ), $number ),
			// translators: placeholder is number of years. (e.g. "Bill this every year / 4 years")
			'year'  => sprintf( _nx( 'year',  '%s years',  $number, 'Subscription billing period.', 'woocommerce-subscriptions' ), $number ),
		),
    		$number
	);
	
	return ( ! empty( $period ) ) ? $translated_periods[ $period ] : $translated_periods;
}

/**
 * Filter and change periods.
 *
 * @param array  $periods
 * @param string $number
 */
function jck_filter_subscription_periods( $periods, $number ) {
	return array(
		// translators: placeholder is number of days. (e.g. "Bill this every day / 4 days")
		'day'   => sprintf( _nx( 'jck day',   '%s jck days',   $number, 'Subscription billing period.', 'jck' ), $number ),
		// translators: placeholder is number of weeks. (e.g. "Bill this every week / 4 weeks")
		'week'  => sprintf( _nx( 'jck week',  '%s jck weeks',  $number, 'Subscription billing period.', 'jck' ), $number ),
		// translators: placeholder is number of months. (e.g. "Bill this every month / 4 months")
		'month' => sprintf( _nx( 'jck month', '%s jck months', $number, 'Subscription billing period.', 'jck' ), $number ),
		// translators: placeholder is number of years. (e.g. "Bill this every year / 4 years")
		'year'  => sprintf( _nx( 'jck year',  '%s jck years',  $number, 'Subscription billing period.', 'jck' ), $number ),
	);
}

add_filter( 'woocommerce_subscription_periods', 'jck_filter_subscription_periods', 10, 2 );