do you say happy birthday to a person who practices Taoism?

I have an instructor who practices this religion and wonder if it would offend him to give a birthday card, cake, etc.

I don't think a Taoist would get bent out of shape over that.

I may be wrong but I think the standard practice in the culture would be fine for them.

They may not make a big deal of it being their birthday but there is nothing in their philosophy that would forbid this.

Happy Birthday is a widespread majorly accepted acknowledgment of the birth of the person on a particular day. Any faith that is popular enough to know about is going to accept the greeting. And who doesn't love cake? Be careful though....ask if he/she's a vegan or lactose and tolerant...so you can make the cake or buy the cake for them to their liking...after all it's their birthday.

No, it certainly wouldn't offend him. Why should it? Taoism is more of a philosophy than a religion. I hate to use the word, because it's superior to Stoicism, but it's sort of like a pro to-stoicism. It takes a great deal for anything to 'get to us,' or offend us. We're usually pretty content. I'm sure S/He would appreciate the gesture.

No. In fact you could bake a cake in the shape of the animal that represents the year of their birth

It is rarely wrong to express your sentiments in your own way, showing the due respect for a person in their position.

A birthday card (Probably not a joke-sort card, as it doesn't seem that this is the sort of relationship you have with this instructor) is likely a good gesture.

It doesn't seem that you know a great deal about the Tao, and as such, I don't think he expects you to understand it. If you would like to read one translation, look here:
http://acc6.its.brooklyn.cuny.edu/~phalsall/texts/taote-v3.html

It might help you get an idea of what it is.

He was born, wasn't he?
.