What calendar is used by Muslims?
Islamic calendar
1 Muharram: Islamic New Year.
10 Muharram: Day of Ashura. For Sunnis, the crossing of the Red Sea by Moses occurred on this day. For both Shias and Sunnis, the martyrdom of Husayn ibn Ali, the grandson of Muhammad, and his followers.
12 Rabi al-Awwal: Mawlid or Birth of the Prophet for Sunnis.
17 Rabi al-Awwal: Mawlid for Shias.
27 Rajab: Isra and Mi'raj for the majority of Muslims.
15 Sha'ban: Mid-Sha'ban, or Night of Forgiveness. For Twelvers, also the birthday of Muhammad al-Mahdi, the Twelfth Imam.
1 Ramadan: First day of fasting.
27 Ramadan: Nuzul al-Qur'an. The most probable day Muhammad received the first verses of the Quran. (17 Ramadan in Indonesia and Malaysia)
Last third of Ramadan which includes Laylat al-Qadr.
1 Shawwal: Eid ul-Fitr.
8–13 Dhu al-Hijjah: The Hajj to Mecca.
9 Dhu al-Hijjah: Day of Arafa.
10 Dhu al-Hijjah: Eid al-Adha.