Let us trace back the history of the All Saints' Day (a.k.a. All Hallows' Day) on NOV-1. Actually, the holiday was first celebrated on MAY-13 when Pope Boniface IV dedicated the Pantheon in Rome to the Virgin Mary. The date was later changed to NOV-1 by Pope Gregory III who dedicated a chapel in honor of All Saints in the Vatican Basilica. Pope Gregory IV later extended the feast to the whole church.
The Eastern Orthodox churches celebrate All Saints Day in the springtime -- the Sunday after Pentecost.
All Souls' Day (a.k.a. the Day of the Dead) which is normally celebrated on NOV-2. When NOV-2 is a Sunday, the celebration is held on the following Monday. This is a day for prayer and almsgiving in memory of ancestors who have died. Believers pray for the souls of the dead, in an effort to hasten their transition from Purgatory to Heaven. It is primarily celebrated by Roman Catholics.
So thats it, until now we are still celebrating it.