ThunderBirthDay is an extension that displays birthdays from the Thunderbird address books as events in Lightning. Install Lightning, MoreColsForAddressBook and ThunderBirthDay, and then create a new local calendar choosing ThunderBirthDay as provider.
WHAT’S NEW IN VERSION 0.8
Version 0.8 added Finnish locales and updated compatibility information for Seamonkey 2.5 and Thunderbird 8.0.