Praise be to Allah.
It is not permissible to participate in Christmas festivities by offering gifts, taking time off work, putting up decorations, and the like. It is also not permissible to offer congratulations on the occasion of these festivals, because they are innovated and haraam festivals that are connected to corrupt beliefs. Moreover, celebrating them is an imitation of the Christians, and that is emphatically haraam, because the Prophet (blessings and peace of Allah be upon him) said: “Whoever imitates a people is one of them.” Narrated by Abu Dawood (4031); classed as saheeh by al-Albaani in Irwa’ al-Ghaleel (5/109)
And Allah knows best.