Martyrdom of Lady Fatima Masuma (S.A)

There is no difference of opinion about the fact that Lady Fatima Masuma (A) died in Qom in the year 201 A.H. The year of her death is further corroborated by the tiles in her shrine, dating back from centuries ago, which have the same date written on them.{1}
However, there are various possibilities about the month and day of her death:
1. 10 th Rabī` al-Thānī {2}
2. 12 th Rabī` al-Thānī {3}
3. 8 th Sha`bān {4}
There is no evidence to say which of the three dates is correct, and so the scholars have decided that because the first and the second dates are so close together, the mourning for the death of this noble lady should be over a three day period (10th, 11th and 12th of Rabī` al-Thānī).
This three day period is called: “ايّام معصوميّة” – “the days of Masuma”.
Lady Fatima Masuma (A) was about 28 years old when she died, although some scholars have said that at the time of her death her age was 18 (from the mistake of the year of her birth - 183 A.H instead of 173 A.H) and others have said her age was 23, but this last narration is not very reliable, due to its weak chain of transmission.

Footnote:
1) Hasan ibn Muhammad Qummī, Tārikh-e Qadīm-e Qum, p. 213; Bihār al- Anwār, vol. 48, p. 290; Sayyid Muhsin Jabal `Āmilī, A`yān al-Shī`a, vol. 8, p. 391; Shaykh `Abbās Qummī, Muntahā al-Āmāl, vol. 2, p. 242; Sayyid Hasan al-Amīn, Dā’irat al-Ma`ārif, vol. 3, p. 231.
2) Mīr Abū Tālib Tabrīzī, Wasīlat al-Ma`sūmīn, p. 65; Sayyid Mahdī Mansūrī, Zindagāni-ye Hadrat-e Ma`sūma, p. 37, `Alī Akbar Mahdīpūr, Zindagāni-ye Karimah-ye Ahl al-Bayt, p. 105.
3) Mustadrak Safīnat al-Bihār, vol. 8, p. 257.
4) Shaykh Hurr ‘Āmilī, Risālat al-`Arabīyah al-‘Alawīyah, p. 11.
References: www.alhassanain.org