All Saints' Day (also known as All Hallows' Day or Hallowmas) is the day after All Hallows' Eve (Halloween). It is a feast day celebrated on November 1st by Anglicans and Roman Catholics.
It is an opportunity for followers to remember all saints and martyrs throughout Christian history. As part of this day of obligation, followers are required to attend church and try not to do any servile work.
Remembering saints and martyrs and dedicating a specific day to them each year has been a Christian tradition since the 4th century AD, but until 609AD when Pope Boniface IV designated May 13th to remember all martyrs was there a designated day.
Over 200 years later, in 837AD, Pope Gregory IV extended the festival to remember all the saints and set November 1st as the date.All Souls' Day directly follows All Saints' Day and is an opportunity for Anglicans and Roman Catholics to commemorate the faithful departed.