Mourning Ceremony on Demise of Prophet Muhammad, Imam Al-Hasan, Imam Al-Ridha at Karbala Center in Orebro, Sweden.
28th Safar: Demise of Prophet Muhammad (S) at the age of 63, (May 25, 632 CE) and Martyrdom of Imam Al-Hasan al-Mujtaba (A), the third Imam of Shia Muslims (March 27, 670 CE). Imam al-Rida (A) (b. 148/766) was martyred by the poisoned fruit al-Ma'mun gave him. This happened on the last day of Safar which would be whether 29 or 30 of Safar. (September 5, 818).
Source: Abna24