Snippet to change the estimated delivery time format on the cart or checkout page. WooCommerce FedEx Shipping Plugin: https://www.pluginhive.com/product/woocommerce-fedex-shipping-plugin-with-print-label/

function.php

add_filter( 'wf_fedex_estimated_delivery',  'wf_update_delivery_time', 15, 2 );
function wf_update_delivery_time($label, $est_delivery){
    $date = explode( '-', $est_delivery['fedex_delivery_time'] );
    if( sizeof($date) < 2 ){
        return $label;
    }

    $d = $date[0];
    $m = $date[1];
    $y = '20'.$date[2];
    
    $delivery_time =  date("l, F jS Y", strtotime($y."-".$m."-".$d)); //(Eg: Tuesday, September 13th 2017).
    return "<br /><small>Est delivery: $delivery_time</small>";
}