the whole reason I say this is because under your contact list and you edit a person, for instance my girlfriend, I went down to "add field" saw what there was and then saw "add date" clicked it and then saw the option "anniversary" as a reminder so I immediatly called her up asked her when it was set it in my phone and now am prepared thanks iPhone for saving me a headache in the future!!!
-GHST

-GHST