Birthdays? Christmas? New Years? Valentines? Thanksgiving? Halloween? Any other Kafir holidays? To all of the above: Absolutely, emphatically forbidden by Allah and His Messenger, Peace and Blessings be upon him. How about innovated Muslim holidays? The Mawlid - the birthday of the Prophet? It was a deviated holiday started by the Shi'a and propagated by the Sufis in the fourth century after the Prophet (peace and blessings be upon him)! The Prophet and his companions never celebrated it! Then what holidays are permissible? The Messenger of Allah (Peace and Blessings be upon Him) said:

 

كَانَ لَكُمْ يَوْمَانِ تَلْعَبُونَ فِيهِمَا وَقَدْ أَبْدَلَكُمُ الله بِهِمَا خَيْرًا مِنْهُمَا: يَوْمُ الفِطْرِ وَيَوْمُ الأَضْحَى

 "You used to have two days you used to celebrate, and Allah replaced them both with two that are better than them: The Day of Fitr and the Day of Adha (the two Eids)" - Recorded by Nasa'i