Keep it simple in my opinion. My wife's bday was almost exactly 3 months after BD and I texted her "Happy bday. Hope you have a good one".

Me:38, Wife:36
M:8
T:13
No kids
Bomb:3/10/13
W moved out:3/30/13
Started D paperwork: 10/14/13
D final: 12/30/13
To a future of love and happiness...