Today is Eid al-Adha, the Feast of Sacrifice in Islam, honoring the willingness of Abraham (Ibrahim) to sacrifice his son, in submission to God's command. The day falls at the end of the annual Hajj. As this site indicates, "At dawn on the day of Eid, Muslims recite the traditional declaration of faith, the Takbir, followed by the pre-sunrise communal prayer, Salat al-Eid, which is also said on Eid al-Fitr. Worshipers then greet friends with the traditional Arabic salutation of Eid Mubarak (“Have a blessed Eid”) and exchange gifts. In a symbolic act, Muslims who can afford it slaughter a cow, goat, sheep or camel, keeping a portion to feed themselves and distributing the rest to friends, family and the needy. Those who can't afford it buy meat from a Halal butcher to distribute. Giving out this meat, in addition to the morning prayers, is considered an essential component of Eid al-Adha." See also this site.
This year's Hajj has been marked by tragedy: http://www.ibtimes.co.uk/eid-al-adha-2015-100-dead-390-injured-hajj-mina-stampede-1520986