For Muslims, the month of Ramadan is a time to reread the Koran, focus one's faith, be charitable and commune with family and friends in celebration of life and God.
The belief is that acts of piety, or even everyday kindnesses, are rewarded even more generously by the Almighty during Ramadan.
Terrorists, particularly members of Isis (Islamic State), espouse a heinous ideology in which such acts of piety include the murder of those they consider infidels. To kill and martyr oneself during Ramadan is encouraged by such extremists.
The collision of Islam's peaceful and joyous Ramadan traditions with terrorists' warped version of them produces a unique kind of dissonance and heartbreak. Most of the victims of Islamist terrorists are other Muslims, after all.
For instance, Isis has bombed a popular shopping street in Baghdad on Ramadan two years in a row. Last year's attack was the worst Baghdad had seen, with more than 300 people either blown up or dead in a fire that subsequently swept through a shopping arcade. This week, 17 people were killed and more than 30 were injured at an ice-cream parlor where families were enjoying dessert after a day of fasting.