The account of the last day of her life clearly shows what kind of a lady was this daughter of Holy Prophet Muhammad (saw). It was 3rd day of the Islamic Lunar Calendar month,Jamadi al-Thani, year eleven after Hijrah. Fatimah Zehra (sa) told the household that she was feeling better, the pain in her ribs and in her hand was not so severe and that her fever had come down. Then she started bathing the children, immediately Imam Ali (as) and Bibi Fizza (ra) came to her assistance. She got those children bathed, dressed and fed, then sent them away to her cousin.
Imam Ali (as) was surprised to find that his dear wife, Fatima Zehra (sa) had left her bed and had started doing the housework; he asked her about it and she replied: "This is the last day of my life. I wanted to wash my children's hair and clothes, because they will soon be orphans, without a mother!"
Imam Ali (as) then asked her about the source of knowledge of this news (the day of her departure). Fatima Zehra (sa) told him that she had seen the Messenger of Allah, Muhammad (saw) in her dream and he had told her that she was going to join him that night. She then asked Imam Ali (as) to execute her will.
Imam Ali (as) said: "Instruct me to do anything you wish, daughter of Holy Prophet Muhammad (saw)." Imam Ali (as) then asked everyone to leave the house and he sat next to her.
Fatima Zehra (sa) started: "Cousin, my dear husband, you know very well why I did all that. Please excuse my fussiness; they have suffered so much with me and during my illness that I want to see them happy on the last day of my life. I am happy and also I am sad. Happy I am that my troubles will shortly be over and I shall meet my father and sorry I have to part with you."
Fatima Zehra (sa) continued: "Cousin, my dear husband, you are not accustomed to me being a False teller, not devoted, or have I disobeyed you since I have become your companion?"
Imam Ali (as) said: "Allah (SWT) forbids! You are more knowing of Allah (SWT), more devoted, more pious, more honorable and more fearing of Allah (SWT) than (to give me a reason) to reprimand you for disobeying me. Surely it is very painful for me to be separated from you and to lose you; but it is an inevitable destination. By Allah (SWT), you have renewed the sorrow I have just encountered with the death of Messenger of Allah, Muhammad (saw); surely your death and departure will be a great calamity, but to Allah we belong, and to Him is our return. (Noble Qur'an, 2:156)
What a painful, bitter and sad calamity. Surely this is a calamity for which there is no console and a disaster for which there is no compensation."
Then they both cried and Imam Ali (as) embraced her head and said: "Instruct me to do anything you wish; you certainly will find me devoted and I will execute everything that you command me to do. I shall also put your matters over mine."
Fatima Zehra (sa) said: "May Allah (SWT) reward you with the best of goodness. Cousin, firstly I ask you to marry anybody you like after my death, but you must marry my niece Umamah; surely she will be to my children as I was. Besides, men cannot do without women. She loves my children and Hussain is very much attached to her. Let Fizza remain with you even after her marriage, if she so desires, she was more than a mere servant to me. I loved her like my daughter."
Fatima Zehra (sa) then added: "I ask you not to let anyone who did injustice to me to witness my funeral, for they certainly are enemies of mine, and the enemy of Messenger of Allah, Muhammad (saw). Also don't give them the chance to pray over me, nor to any of their followers. I want you to wash me at night, put the shroud on me, perform the prayer upon my body, and bury me at night when eyes are rested and sight is put to sleep. And after my burial, sit beside my grave and recite Noble Qur'an for me."
Let my death do not dishearten you, you have to serve Islam and humanity for a long time to come. Let not my sufferings embitter your life, promise me cousin, my dear husband." Imam Ali (as) said, "yes Fatima, I promise" "Cousin, my dear husband", she continued, "I know how you love my children but be careful of Hussain. He loves me dearly and will miss me sadly, be a mother unto him. Till my recent illness he used to sleep on my chest, he is already missing it." Imam Ali (as) was caressing the broken hand, his hot and big tears dropped on her hand. She looked up and said, "Do not weep cousin, my dear husband; I know with a rough outward appearance what a tender heart you possess. You already have borne too much and will have to bear more.
Fatimah Zehra (sa) was ready to meet her Lord. She bathed, than lay down in her garment. She then instructed Asma bint Umays to wait awhile and then to call her name; if there was no answer, this would mean that Fatimah Zehra (sa) had departed towards her Lord.
Asma bint Umays waited awhile, then called Fatima's name, but there was no answer; Asma bint Umays repeated the call: "O daughter of the chosen Muhammad! O daughter of the most honorable of them whom women bore! O daughter of the best of those who have walked on gravel! O daughter of him who 'was at a distance of but two bow-lengths or (even) nearer.'" (Noble Qur'an, 53:9)
There is no answer, silence overwhelms the house, Asma bint Umays then proceeds towards Fatima Zehra (sa) and finds her dead, the soul had departed to join her Father, Holy Prophet Muhammad (saw) in the realm of Grace, Mercy and Might.
At that point, Imam Hassan (as) and Imam Hussain (as) entered and asked Asma bint Umays: "Where is our mother?" "Our Mother did not used to sleep at this time of the day!"
Asma bint Umays replied: "O sons of the Messenger of Allah! Your mother is not sleeping, she has passed away!"
While Imam Hassan (as) heard such words, he fell on the body of his mother and kissed her face and addressed her: "Dear mother! Please talk to me before I pass away."
Imam Hussain (as) came near and kissed her mother's feet and said: "Dear mother! I am your son Hussain, talk to me before I pass away."
Then, Imam Hussain (as) turned towards Imam Hassan (as) and said: "May Allah console you for our Mother!"
There are two different narrations about where Imam Ali (as) was at the time of Fatima Zehra's (sa) death? One of them says he was with Fatima Zehra (sa) at the time of her death. And another says as follows:
Imam Ali (as) was at the Mosque. Imam Hassan (as) and Imam Hussain (as) went to the Mosque and broke the news to their father. As soon as Imam Ali (as) heard their words, he fell unconscious. When he regained consciousness, he said: "Who will console me now, daughter of Muhammad? You used to console me, so who will take your place now?" Fatimah Zehra (sa) died very young as Imam Ali (as) says, "A flower nibbed in the bud, it was from Jannat (Heaven) and it went to Jannat, but has left it's fragrance in my mind."
The Hashemite women were then gathered to receive the news of the great calamity. Yes, the calamity befell them once more, while the blood was still flowing from the wound of losing Prophet Muhammad (saw).
When people of Medina realized Fatimah Zehra's (sa) martyrdom, they gathered in front of her house and waited for the burying ceremony. But it was announced that the ceremony was delayed. At night, when all people were asleep, Imam Ali (as) started to wash Fatima's (sa) body and shroud her, in absence of the people, who had oppressed her greatly, according to her will. When ablutions was finished, he told Imam Hassan (as) and Imam Hussain (as) - who were only two little children at that time - to call some of Prophet Muhammad's (saw) true companions (Sahabah) whom Fatima Zehra (sa) was satisfied with, to participate in the burying ceremony. They were not more than 7 as it has been narrated. After they arrived; he said prayers and then buried her while his children were sad and were secretly crying for losing their mother.
There is one narration with 2 interpretations that the demise of Fatima Zehra (sa) occurred either 75 days or 95 days after demise of Prophet Muhammad (saw). As we know 28th Safar is the day of demise of Prophet Muhammad (saw). So, if it was 75 days assuming that Safar, Rabi al-Awwal, Rabi al-Thani, Jamadi Al-Awwal could be 30 days so 75 days would 13th, 14th or 15th of Jamadi Al-Awwal.
And as for 95 days count then Shahadat falls on the 3rd Jamadi al-Thani. Because we do not know the exact date we call this period between 13th, 14th, 15th Jamadi Al-Awwal to 3rd Jamadi al-Thani as Ayyame Fatimiyya.