Holiday alerts to family and friends

I am devel开发者_StackOverflow中文版oping an android app that will send out SMS on birthdays,new year etc . I was able to add my own field for contact s DB , but is this a good idea modifying contacts DB ? There s also one more way , ie to have my own DB , but do i update this if the user adds new contact s ?? any ideas ?

You could use your own DB and try to register a registerContentObserver on the contacts database to be notified when it's content changes.