Couldn't figure out how to use Woocommerce Bookings functions to show if a product was fully booked or not, so came up with this.

get-product-availability.php

function get_product_availability() {

    global $product, $post;
	// Get dates from custom field
	$start_date = get_field('start_date');
	$end_date = get_field('end_date');

	// Get into class
	$WC_Product_Booking = new WC_Product_Booking($product);	

	// Get resources for this product
	$resources = $WC_Product_Booking->get_resources($product->ID);

	// Add all resource quantities of this product together
	$qtyResources = 0;
	foreach ( $resources as $resource ) {
	  $qtyResources += get_post_meta($resource->ID, 'qty', true);
	}

	// get the number of bookings for this product on the start date
	$bookedPosts = get_posts(array(
	    'post_type'   => 'wc_booking',
	    'post_status' => array('unpaid', 'pending-confirmation', 'confirmed', 'paid'),
	    'posts_per_page' => -1,
	    'fields' => 'ids',
	    'meta_query' => array(
				array(
					'key' => '_booking_product_id',
					'value' => $post->ID
				),
				array(
					'key' => '_booking_start',
					'value'   => $start_date."000000"
				),
			)
	  )
	);
	$productBookings = count($bookedPosts);

	// If total resource quantity is equal to confirmed bookings then it's fully booked
	if ($qtyResources <= $productBookings) {
		$fullyBooked = true;
	} else {
		$fullyBooked = false;
	}

	// Do something with it
	if ($fullyBooked == true) {
		echo "fully-booked";
	}
	if ($fullyBooked == false) {
		echo "available";
	}

}

I found out that woocommerce bookings plugin was storing dates without '-', so 2016-02-01 was going in as 20160201

Thank you for sharing this.... OMG you saved my world there - I have been pulling my hair out wondering why a UNIX timestamp was converting to a very strange date - when all along the _booking_start like this "20230224000000" is actually the date like this 2023-02-24-000000