以正确的顺序回显变量

Set-up

I've decided to try a little bit of PHP myself, I'm a total beginner.

I run a WooCommerce shop and want to dynamically display the expected delivery date range on each product page.

The delivery date range is today's date plus 3 and plus 4 days, e.g. today is the of 10th October so the delivery date range is 13 and 14 October. On each product page it should therefore mention,

Delivery between Oct 13 and Oct 14

I know where to write the code such that it displays where I want it to appear on the product pages.

I also know how to dynamically update the delivery dates.

Problem

Echo mixes the variables, instead of,

Delivery between Oct 13 and Oct 14

it states,

Delivery between and Oct 13Oct 14

My Code

function my_custom_action() { 

    $plus3 = strtotime("+3 day");
    $plus4 = strtotime("+4 day");   
    $date_low = date('M d', $plus3);
    $date_high = date('M d', $plus4);
    $start_text = _e('Delivery between ','woodmart');
    $end_text = _e(' and ','woodmart');

    echo $start_text, $date_low, $end_text, $date_high ;
};     
add_action( 'woocommerce_single_product_summary', 'my_custom_action', 15 ); 

I need $start_text and $end_text in functions so the strings are translatable.

Preferably I also have the months (e.g. Oct) translatable, but for now I'd already be very happy to know how I get all variables echoed in the desired order.

This can be resolved using string interpolation.

for eg.

$name = "PHP"; echo "I am reading {$name}POT"; // output: I am reading PHPPOT

here's the link to a much more detailed reference : variable-interpolation-in-php