The short answer
Muharram opens the Islamic year. Its tenth day, Ashura, has different emphases across Muslim traditions, including voluntary fasting and the mourning of Husayn’s death at Karbala.
What the new year marks
Muharram is the first month of the Hijri calendar. The calendar’s era is associated with the year of Muhammad’s migration from Makkah to Madinah. Beginning a new year and celebrating a festival are not the same thing. Communities may use the occasion for reflection, while the month has particular solemnity for those commemorating Karbala. Sahih Muslim also preserves a Sunni report giving special importance to voluntary fasting in Muharram.
Ashura in Sunni observance
Ashura falls on the tenth of Muharram. A report in Sahih al-Bukhari connects fasting that day with Moses and the Israelites being delivered from their enemy. Sunni practice commonly gives voluntary fasting a prominent place. That report explains one religious account of the observance. It should be identified as a transmitted tradition, rather than treated as independent historical verification of the date of the events involving Moses.
Ashura and the memory of Karbala
For Shia Muslims, Ashura is especially a day of mourning for Husayn, Muhammad’s grandson, and those killed with him at Karbala in 680 CE. Remembrance can involve gatherings, recitation, accounts of suffering and reflection on loyalty and resistance to injustice. Particular practices vary. The significance of this loss cannot be captured by listing Ashura simply as a happy festival. Nor does a description of one community’s mourning practice represent every Shia Muslim.
How to approach the differences respectfully
Ask what the occasion means to the person or community you are visiting. Avoid assuming that a celebratory greeting suits a mourning gathering. Learn the event’s history before drawing conclusions from an unfamiliar ritual. A helpful comparison keeps the Sunni fasting reports and Shia accounts of Karbala distinct while recognizing that people’s attachments can overlap. The sources below provide starting points from within those traditions. They do not make every historical interpretation or devotional practice uncontested.
What this establishes, and what it does not
Sunni and Shia are broad categories with internal diversity. These summaries explain major emphases without treating fasting, mourning or local customs as uniform across all Muslims.
Sources & reading notes
- Fiqh Council of North America: Islamic calendarShows Muharram as the opening month of the Hijri year.
- Islamic Relief: the beginning of the Islamic new yearExplains the calendar’s connection with the year of the Hijrah.
- Sahih Muslim 1163aA Sunni report concerning fasting in Muharram.
- Sahih al-Bukhari 2004A Sunni report connecting Ashura fasting with Moses and the Israelites.
- Al-Islam.org: AshuraA Shia account of Husayn’s death at Karbala and the observance’s commemorative significance.
Sources checked for this editorial draft on 20 October 2026. Specialist review remains pending. A citation identifies a source; it does not make every interpretation uncontroversial.