When filling up contacts in google I normally enter the birthday as well. This information is then displayed in a Read-Only-Calendar in Google-Calendar.So far I do not see any way to get notifications on these dates. Do you know if this is possible?
Birthday calendar notification
google calendar;notifications
From all I've heard & read, this isn't possible. The only way I've got around it is by copying these auto-generated events to another calendar and then adding a notification. One advantage of this is you choose which ones you get an alert for, but of course it's not ideal.