also abul-fidah vol. 2 pg. 45 mentions the birth of hazrat to have occurred in the year 255.
«Mahdi and his birth»
a group of scholars, amongst them being the learned and mystic traditionist muhammad khawja . bukhari in his book 'fasl-ul-khetab' (as per what has been written on page 387 of 'yanabi-ul-muwadda') have narrated that hadimah, the daughter of hazrat imam muhammad jawad (a.s.) and aunt of abu muhammad hassan askari (a.s.) used to always pray and lament and ask Allah to make her succeed in meeting hazrat's son. thus it was about the midnight of 15th shaban, 205 when she visited hazrat hassan and the latter asked her to stay with them because of the event which lay ahead. so she stayed behind in the very place. it was the time of dawn when nargis (mother of hazrat Mahdi) felt uneasy. then hakimah hastened towards her and a few moments later nargis delivered a blessed child while circumcised. when hakimah's looks fell on the child she took him in her arms and went towards hazrat hassan (a.s.). hazrat embraced him and rubbed his blessed hands over his back and eyes and then placed his mouth over his mouth. thereafter he recited 'azan' (call to prayer) in his right ear and 'eqamah' (establishment of prayers) in his left ear and then said: 'o aunt, take him to his mother.' hakimah obeyed and took the child back to his mother. hakimah says: "once again, i visited abu muhammad hassan askari's house. all of a sudden, i saw hazrat carrying a child who was wearing a yellow dress and the baby's face was beaming with light." then, his love superseded my heart and i said: 'o my master, what have you to say about this blessed child? he replied: 'o aunt, he is the same expected one about whom we were given glad-tidings.' then, i threw myself on the ground and prostrated as an expression of thanksgiving.(83)
author says: 'what we have narrated before and what we shall narrate later on, necessarily proves his birth because those tradition comprises several parts. one of the parts indicates that he is the twelfth successor while another shows that he is the twelfth legatee. still another portion indicates that he is the twelfth imam and leader and another indicates that he is the ninth from the progeny of hussein (a.s.). others reveal that he is the fourth from the offspring of ridha (a.s.) and yet others reveal that he is the son of hazrat abu muhammad hassan askari. another part indicates his occultation and the fact that he is concealed from the public-view and cannot be recognized.
these 'mustafiza' and rather 'mustawatir' traditions clearly stipulate and or necessarily indicate that Mahdi, the expected one is the immediate son of imam abu muhammad hassan askari. moreover this indication is so manifest and evident that no one has any doubt in it and none disputes.
now we say: based on this, we are bound to accept one of t he following:
firstly that, we reject the afore-said traditions from the view-point of chain of transmission and weakness in indication and as a result deny the afore-mentioned claims.
reply: anyone who has reviewed the traditions and gone through the books of 'rijal' (distinguished scholars) can never ever imagine such an affair because a number of partisans of traditions have confessed the authenticity of some of them and have given evidence of their credibility and acceptability. rather, hakem who is the leader of this art has himself recorded some of them and as per the views of bukhari and muslim, has reckoned them to be correct.
thus man's conscience itself bears testimony to this objection.