Eid al-Fitr, the three-day festival of thanksgiving to mark the end of the holy month of Ramadan, is often compared to Christmas.
It's a time for millions of Muslims around the world to enjoy time with friends and family and share gifts.
But, in the wake of a devastating attack by ISIS that killed more than 200 people in a busy shopping district in Baghdad on Sunday, many Muslims in Toronto say they have chosen not to celebrate the holiday.
Hassan Jaber, an Iraqi-born mechanical engineer who lives in Ajax, Ont., told CBC News he was appalled at the timing of the attack, the deadliest seen in Baghdad in years.
"We can't celebrate and be happy and walk around smiling when 230 men and women were killed for no reason," Jaber said. "I'm not celebrating Eid this year, and I know a lot of people that are doing the same thing."
He said the attack proves that the so-called Islamic State is anti-Islamic.
"What more proof do you need than them targeting their own during their own blessed month?" Jaber asked.
Another Muslim in mourning as Ramadan ends is Fahad Al, the humanitarian co-ordinator for the Canadian Aid Organization for Iraqi Society Rehab.
"I'm not celebrating, there's no way," Al said. "Me and my family, we decided for Eid, we're not doing anything."
Al and Jaber are helping organize a vigil for the Baghdad victims Wednesday night at Yonge-Dundas Square.
"The initiative is for Baghdad, but we will also be raising flags for Saudi Arabia, Turkey, Afghanistan and Pakistan because they all have seen a lot of massacre," Al said on Metro Morning today.
"As Arabs, as Canadians and as humans, we should really stand up and say enough."