All Saints Day is a Christian holiday commemorating all known and unknown Christian saints.
Why is it important?
All Saints' Day, also known as All Hallows' Day, the Feast of All Saints, the Feast of All Hallows, the Solemnity of All Saints, and Hallowmas, is a Christian solemnity celebrated in honor of all the saints of the church, whether they are known or unknown.
In the Western Christian practice, the liturgical celebration begins at Vespers on the evening of 31 October, All Hallows' Eve (All Saints' Eve), and ends at the close of 1 November. In Eastern Orthodox Christianity, the day is observed on the first Sunday after Pentecost.
It should not be confused with All Souls' Day, which is observed on November 2, and is dedicated to those who have died and not yet reached heaven.