The WooCommerce Lead Time plugin comes with two types of product lead time:
Static lead times - You add some fixed text to display on the page. For example, if you add a static lead time of "5 days" then "5 days" will always appear. This is the best option if your products always have consistent waiting times.
Dynamic lead times - You set a date when the product will become available, and the plugin automatically calculates the lead time based on this date. For example, if you have ordered stock to arrive on 30th November and it is currently 10th November then the lead time will be displayed as "10 days". This is the best option if a product is due to arrive on a particular date, after which it will become available.
You can use a combination of static and dynamic lead times for different products and stock statuses.