Halloween or Allhalloween is a celebration of countries on 31 October, the eve of the Western Christian feast of All Hallows' Day. It begins the three-day observance of Allhallowtide, the time in the liturgical year dedicated to remembering the dead, including saints hallows, martyrs, and the faithful .
to recall to the mind by an act or effort of memory; think of again:
I'll try to remember the exact date.