Q: Can we wish our friends on birthdays, anniversaries, etc. and can we attend parties on these occasions? Some people say there is nothing wrong in attending such parties.
A: Wishing people happy birthday and anniversary, attending such parties and anniversaries, are all customs of the non-Muslims and not permissible. Birthday parties originate from the customs of Pagans and idol-worshipper, so Islamically it should be avoided. Furthermore, much money is wasted on these unnecessary parties, and in such events there will always be mixed gatherings which makes it all the more haraam.