This message is from: "Larson" <[EMAIL PROTECTED]> The easiest method I've ever seen: Add 1 week and subtract 1 month. Example: If the mare was serviced 1 March 2000: 1st plus 7 days = 8th and March minus one month = Feb. So foaling date is Feb 8, 2001. Simple and you don't have to look up anything or count up actual days.