Celebrating Valentine’s Day is not permissible because it is an innovated festival and it promotes love and infatuation. For more, please see the detailed answer.

It is not permissible for the Muslims to exchange greetings on the occasion of the Gregorian New Year, and it is not permissible for them to celebrate it

It is not permissible for a Muslim to take part in the festivals and innovated celebrations of the non-Muslims, such as Easter and Christmas.

What is forbidden with regard to congratulating the Christians on the occasion of their festivals is expressing joy to them, being overly polite and showing approval of their actions, even if that is only expressed outwardly without feeling it inwardly.

• It is not permissible for the Muslim to take part in the religious celebrations of the non-Muslims and it is not permissible for them to congratulate them. • It is permissible for Muslims to attend celebrations of the non-Muslims on their special occasions such as marriage, recovering from sickness and return from travel on condition that it serves a legitimate Shar`i interest. • It is not permissible for the Muslim to attend celebrations of the non-Muslims or the Muslims in which there is propagation of any false religion or ideology. • It is not permissible for the Muslim to attend any celebration of the non-Muslims or the Muslims if it is done in the manner of a repeated festival every year or every month and so on, like birthdays and Mother’s Day. • It is not permissible for the Muslim to attend any celebration of the non-Muslims or the Muslims that is a prohibited celebration in terms of the occasion, such as Valentine’s Day. • It is not permissible for the Muslim to attend any celebration of the non-Muslims or the Muslims in which there is mixing with women, or music, or where forbidden food is eaten.

There is nothing wrong with accepting a gift from a non-Muslim on Christmas and that is not regarded as participating in it or approving of it, rather it should be accepted as an act of kindness with the aim of softening his heart and calling him to Islam.