Zero-day attack, exploitation of unpatched software vulnerabilities
The Church of Jesus Christ of Latter-day Saints | Green Day | One Day International | New Year's Day | Boxing Day | Memorial Day | Seventh-day Adventist Church | Labor Day | Doris Day | Earth Day | May Day | Massive Attack | Sandra Day O'Connor | Valentine's Day | Record Store Day | Attack on Pearl Harbor | Mother's Day | Ferris Bueller's Day Off | Bastille Day | Six-Day War | attack on Pearl Harbor | April Fools' Day | Australia Day | Father's Day | Brightest Day | Big Day Out | Macy's Thanksgiving Day Parade | Canada Day | Victory in Europe Day | Long Day's Journey into Night |