when is the date of birth and yorzeit of Avrohom avinu? what day?

Shalom uvracha, The date of birth and yorziet were on the same day. there are two opinions in masechet rosh hoshona 10. according to Rabbi Eliezer he was born on the first of Tishrei and according to Rabbi Yehoshua it was the first of Nissan (see rashash and sefat emet there in masechet rsh hsohona). He was born 1948 years after the world was created. All the best