Which Day is the Day of Ashura?

Hazrat Hakam bin A'raj says that I went to the service of Hazrat Abdullah bin Abbas (may Allah be pleased with them both); he was sitting leaning against the well of Zamzam. I said, "Tell me about the fast of Ashura." He replied, "When you see the crescent of Muharram, start preparing for that day. Then fast on the ninth day." I asked, "Did the Messenger of Allah (peace and blessings be upon him) use to fast on that day?" He replied, "Yes."

It is narrated from Hazrat Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: If I remain alive until next year, I will surely fast on the ninth of Muharram, that is, the Day of Ashura.

Hazrat Ibn Abbas (may Allah be pleased with them both) said that the Day of Ashura is the night of the tenth and the morning of the ninth.

Hazrat Dhahhak says that the Day of Ashura is the ninth of Muharram.

Hasan and Muhammad say that the Day of Ashura is the tenth of Muharram.

Hazrat Saeed bin Musayyib, Hasan, and Hazrat Ikrimah state that the Day of Ashura is the tenth of Muharram.

Hasan says that the Day of Ashura is the tenth of Muharram.

Hazrat Ibn Abbas (may Allah be pleased with them) says that the Day of Ashura is the ninth of Muharram.

Hazrat Shu’bah narrates that Hazrat Ibn Abbas (may Allah be pleased with them) used to fast on the day of Ashura even during travel, and he would also fast one day before and one day after, so that the fast of the day of Ashura would not be missed.

Hasan says that the Day of Ashura is the tenth of Muharram.