Why World Mission Sunday Matters. World Mission Sunday, observed on Oct 20th this year, is not just another Sunday; it is a powerful reminder of our call to be missionaries. The collection taken up on this day is unique as it is mandated by the Code of Canon Law and is essential for the survival and growth of the Church in mission territories. These funds support the pastoral and evangelizing work of the Church, building churches, providing healthcare and education, and training future priests and religious. In places where resources are scarce, your generosity makes a profound difference