Rated 4 out of 5 stars

by Cosmin Tanczel on May 3, 2010 ·

Syncing thunderbird contacts birthdays with google doesnt work. Any ideea when this feature will be available?

This review is for a previous version of the add-on (0.8.13.3). 

by Leni Mayo (Developer) on May 4, 2010 ·

Cosmin, birthday sync is in release 0.8.16 of the addon, currently available for download at zindus.com.

The feature isn't available at addons.mozilla.org yet because the addon has different release streams. addons.mozilla.org gets the most stable releases, but is the least frequently updated. See: http://zindus.com/i/release-streams