Dr. Shaykh. Fauzan bin Salih bin Abdullah Al-Fauzan
Surely among the most important consequence of the attitude of the disbelievers hate is syi'ar away and worship them. While most of their syi'ar is their holiday, whether in relation to place or time. Then a Muslim is obliged to stay away and leave it.
There was a man who came to baginada Apostle sallallaahu alayhi wa sallam to ask for a fatwa because he had cut the animal in Buwanah bernadzar (name of a place), so the Prophet sallallaahu alayhi wa sallam asked him.
"That is: Is there any idols, from the idols of Ignorance that is worshiped?" He replied, "No". He asked, "Is there a place implementation of the feast of feasts them?" He replied, "No". So the Prophet said, "Tepatillah nadzarmu, because it really should not be nadzar in immoral conduct against God in the things that are not owned by the sons of Adam" 
Above hadith shows, not bolehnya slaughter to coincide with God in the place used to slaughter for other than Allah, or in place of pagans celebrated the feast or feast day. Because it means to follow them and help them in syi'ar-syi'ar glorify them, and also because they resemble or be Wasilah that leads to shirk. Similarly, to celebrate the holiday (holiday) they contain wala '(loyalty) to them and support them in turn-syi'ar syi'ar them.
Among the prohibited is showing a sense of joy on their feast day, days off work (school), to cook foods with respect to their feast. And of them again is to use the Gregorian calendar, because it turned the memory of the feast of Christmas for them. Therefore the Companions used the Islamic calendar instead.
Shaykh al-Islam Ibn Timiyah said, "Come celebrate the great days they were not allowed because of two reasons".:
General nature, as has been stated above that it means to follow the Scriptures, that is not in our doctrine and not in kebiaasaan Salaf. Mean follow contain the damage and leave them there are serious benefits menyelisihi. Even if the similarity is something that we do resolve itself, not because take it from them, of which disyari'atkan is menyelisihinya menyelisihiya because there are serious benefits as has been hinted at above. So whoever followed them, he had lost these beneficiaries do not even mafsadah (damage) whatsoever, even more so if he did.
Because it is an innovation that was held inventions. These reasons clearly indicate that the highly unpopular laws like they are in that ".
He also said, "It is not lawful for the Muslims bertasyabuh (resemble) them in things that are special for their holidays, such as, food, clothing, toiletries, lighting candles, dismiss such work and worship habits or the other. It is not lawful conduct feast or give a gift or sell the items needed for the feast. It is not lawful to allow children or others do the game on that day, also may not show jewelry.
In summary, should not be doing something that is characteristic of syi'ar them on that day.
They feast for Muslims to be like the days usually, there is nothing special or particular Muslims did. As if these things done by Muslims on purpose  the different sections of the Salaf and Khalaf consider it makruh. While specialization as mentioned above, there is no difference among scholars, even some scholars consider infidels who do it, because he has glorified syi'ar-syi'ar infidelity.
A section of scholars said. "Anyone who slaughters a goat on their feast day (for the sake of celebrating it), it is as if he had slaughtered a pig". Abdullah bin Amr bin Ash said, "Who would follow for countries' Ajam (non-Islam) and do a celebration Nairuz  and Mihrajan  and resemble them until he died and he has not repented, then he will put together their on the Day of Judgement 
[Copied from the book of lish-At-Tawheed Al-Awwal Shaffil Aliy, edition of Indonesia, the Book of Tawheed a, author Dr. Salih bin Abdullah bin al-Fauzan Fauzan, Dar ul Haq Publisher]
. Hadith Abu Dawud with a chain of transmission in accordance with the terms of Al-Bukhari and Muslim
. Maybe that is the (right) is 'accidentally'.
. Nairuz or Nauruz (Persian) a new day, the feast of the Iranian new year which coincides with the date of March 21-pent.
. Mihrajan, combination of the words mihr (sun) and jan (life or soul), ie in mid-autumn festival, where the air is not hot and not cold. Or is also a term for a party held for a happy day-pent.
. Majmuâ € ™ Fatawa 25/329-330