父亲节快乐 (Traditional: 父親節快樂) = Happy Father's Day ( you may click the Chinese characters to get the pronunciation and click the Play button to listen to the sound). This year it will be on 6/16/2013.
We can say 六月十六號是父親節 ( June 16th is Father's Day ).
On that day, you should call him and say "老豆你好！"
..你好！ means so and so, how are you?
老豆 or 老竇 is an informal way to call daddy.
The Cantonese word 爹地 is actually a borrowed word from English “Daddy"
We often call our elderly daddy 老爹 (Old Dad). Similar to Mandarin.
We should also say " 老竇我好掛住你啊 ！” ( = Daddy, how I miss you! ) if you call home from far away. Take good care of your father and send him more love if you still can. I cannot any more as he passed away many years ago. There's a Chinese saying from a famous peom: 子欲養而親不待 ( When the son wants to support the parents who have passed away. ) A pretty close translation of the sentences in that Chinese poem can be found at Dict.cn: 树欲静而风不止，子欲养而亲不待.