greetings

People congratulating one on one's birthday

Q: Before I had an idea about not celebrating birthdays, but on my first birthday in university, I gave a treat thinking that to feed someone is good, but I don't know if it's correct or wrong! Now, my second birthday is about to come and I don't know what to do if they greet me on my birthday, Alhamdulillah this year it's Sunday (I'll be on leave) but what reply must I give to the messages and phone calls from people who greet me (as I don't want to celebrate/give a treat in the name of a birthday), could you please tell me?

Greeting non-Muslims

Q: I work with non-Muslims so the following situations arise:

1. How should I greet them because if I do not greet them then they feel offended?

2. When they say seasons greetings or compliments of the season at December time, how should I reply?

Saying "Khuda Haafiz"

Q: What is the ruling regarding saying "Khuda Haafiz" when departing from a meeting? I know that it is best to say "Assalamu Alaykum", but since "Khuda Haafiz" also has a good meaning, would it at least be better than saying "Goodbye"?