Is It Haram to Say Happy New Year?
Question

Is it permissible for Muslims to congratulate each other and give du`a on the new year based on the Gregorian calendar without the intention of celebrating it?
Praise be to Allah.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. Both of these matters involve imitation of the non-Muslims, and we have been forbidden to do that.
The Prophet (blessings and peace of Allah be upon him) said: “Whoever imitates a people is one of them.” (Narrated by Abu Dawud, 4031; classed as sahih by al-Albani in Sahih Sunan Abi Dawud)
Moreover, offering greetings on this day that comes back each year comes under the heading of celebrating it and taking it as a festival, which is also forbidden.
For more, please see these answers: 101404 , 21290 , 113064 , 13642 , and 145950 . 
And Allah knows best.