1). To determine a doe's DUE date, enter the date that the doe was bred in "Bred Date" box. Then click on "Calculate." 2). To determine a doe's BREEDING date, enter the date that the doe gave birth in the "Due Date" box. Then click on "Calculate." 3). You can enter the date many ways: March 15, 2007 can be entered as 3/15/07 or Mar 15, 2007 or 15 Mar 2007, or March 15, 2007. Do not enter a dot in your date: Mar. 15, 2007, this will not work. Settled/Bred Date: (Enter the date here) Due Date:                                                                                                                                                     This calculator is based on a 150 day gestation. Due dates may range from 145-154 days of pregnancy.