All Saints Day is celebrated by Catholic and Protestestant churches on Nov. 1.
It has also been called All Hallows' Day, or Hallowmas, a day to celebrate the Christian saints. Nov. 2 is All Souls Day, observing those who have died.
Sources: https://www.catholic.org/calendar/november.php
https://www.christianity.com/church/church-history/all-saints-day-november-1.html