Rabbit Due Date Calculator by Breeders Friend makes calculating and saving all your rabbit kindling and show dates quick and simple. Select either the simple calculator for due date only or the advanced calculator for extended options and dates. Know when to breed in order to hit those critical ages for your upcoming shows by calculating for a specific age at show date. Fully customizable calculations and the ability to add your own. When you are done and need to save the calculated dates simply press a button to add it to your device calendar.