Someone told me that taking a bath at a night time is very sinful and wrong and Islam has told us not to do it. Please answer me I am confused.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

There is no harm on a Muslim to have a bath at night, be it a ritual bath or a usual bath. On the contrary, he is obliged to have a ritual bath if he is for instance in sexual defilement [requires a ritual bath after having had sexual intercourse with his wife] and wanted to pray. We do not know of any evidence saying that it is a sin to have a bath at night, let alone saying that is a major sin to do so.

Imaam An-Nawawi [from the Shaafi'ee school] said in his book Al-Majmoo': 'It is desirable for a pilgrim to perform a ritual bath when he is in Muzdalifah after midnight in order to stand at Al-Mash'ar Al-Haraam and for 'Eed as well.'

Al-Adawi [from the Maaliki school] said: 'It is better (for a person who intends to fast on the following day) to have a ritual bath by night.' That is, it is better for him to take a ritual bath at night than having a ritual bath after Fajr so that the time of Fajr would not begin while he is in sexual defilement.

Finally, it should be noted that a Muslim should not say that something is lawful or forbidden without evidence as this is very serious. Allaah says (what means): {And say not concerning that which your tongues put forth falsely: "This is lawful and this is forbidden," so as to invent lies against Allaah.}[Quran 16:116].

Allaah Knows best.