death - When is Avraham Avinu's Yahrzeit?

I have no sources to provide to this question. Rather I am asking simply. On what day was Avraham Avinu nifter? (pass away.) Do we know at all?

Answer

1. 
   

   In Rosh ha-Shanah 10b-11a, there is a Machaloqet between R. Eli'ezer and R. Yehoshu'a over when, amongst other events, the Avot( Avraham and Ya'aqov) died:

   
   

   
   

   תניא רבי אליעזר אומר בתשרי נברא העולם בתשרי נולדו אבות בתשרי מתו אבות בפסח נולד יצחק בראש השנה נפקדה שרה רחל וחנה בראש השנה יצא יוסף מבית האסורין בר"ה בטלה עבודה מאבותינו במצרים בניסן נגאלו בתשרי עתידין ליגאל
   ר' יהושע אומר בניסן נברא העולם בניסן נולדו אבות בניסן מתו אבות בפסח נולד יצחק בר"ה נפקדה שרה רחל וחנה בר"ה יצא יוסף מבית האסורין בר"ה בטלה עבודה מאבותינו במצרים בניסן נגאלו בניסן עתידין ליגאל

   
   

   
   

   In English( from the Soncino translation, p.25-26 in the PDF, download-able here):

   
   

   
   

   It has been taught: R. Eliezer says: In Tishri the world was created; in Tishri the Patriarchs were born; in Tishri the Patriarchs died; on Passover Isaac was born; on New Year Sarah, Rachel and Hannah were visited; on New Year Joseph went forth from prison; on New Year the bondage of our ancestors in Egypt ceased; in Nisan they were redeemed and in Nisan they will be redeemed in the time to come.
   
   R. Joshua says: In Nisan the world was created; in Nisan the Patriarchs were born; in Nisan the Patriarchs died; on Passover Isaac was born; on New Year Sarah, Rachel and Hannah were visited; on New Year Joseph went forth from prison; on New Year the bondage of our ancestors ceased in Egypt; and in Nisan they will be redeemed in time to come.

   
   

   
   


2. 
   

   R. Shimshon ben Pesach Ostropoli, in his commentary Dan Yadin to Sefer Qarnayim( a Kabbalistic work, which R. Shimshon attributes to R. Aharon ben Avraham of Kardina), says( in Ma'arakhah 6 note 3):

   
   

   
   

   ומיתת האזרחי מוכיח והוא הבשורה הטובה וכו׳, פירש מיתת אברהם הנקרא איתן האזרחי שמת בטבת כנודע מספרי המקובלים בסוד תקבר בשבה טובה ר״ת למפרע טבת והוא הבשורה טובה כנודע, וזה שנרמז בו ר״ל בקרא כדפירשתי

   
   

   
   

   In my translation:

   
   

   
   
   

   And the death of the Ezrachi brings proof and it is the good announcement etc., [it has been] explained the death of Avraham, who is called Eitan ha-Ezrachi, who died in Tevet, as is known from the books of the Mequbalim, is in the Sod of 'Tiqaver be-Seiva Tova' ['thou shalt be buried in a good old age', Bereshit 15:15], it's initials, from back to front, being Tet- Bet- Tav[ spelling Tevet] and this is the good announcement, as is known,and this is what is alluded to in it, i.e. in the writ, as I have interpreted.

   
   

   
   


3. 
   

   The Benei Yissakhar, in Regel Yesharah Ma'arekhet Tet No. 15, when bringing the Sefer Qarnayim and Dan Yadin about Avraham having died in Tevet, questions it, based on the Machaloqet in Rosh ha-Shanah, and answers that Avraham probably died in either Tishrei or Nisan, but was buried in Tevet. His reasoning is that the Pasuq used as proof-text for Tevet mentions Qevurah( burial), not death.

   
   

( It should be noted, that none of these sources give the exact date, but only the month, of Avraham's death.)

So, in conclusion we have:

1. Tishrei( R. Eli'ezer, in Rosh ha-Shanah 10b)


2. Nisan( R. Yehoshu'a, ibid. 11a)


3. Tevet( R. Shimshon ben Pesach Ostropoli, in Dan Yadin, though the Benei Yissakhar says he was only buried then)