I assume the "Ascension day" is Good Friday?
Why then wouldnt Halloween be called All Saints Day?
Ascension Thursday is 40 days after Easter and commemorates the ascension to heaven of the resurrected Jesus. Good Friday is two days before Easter and commemorates the crucifixion of Jesus.
Halloween is a contraction of the Middle English "All Hallow's Even" which in modern English would be All Saint's Eve.
Traditionally, All Saint's Eve was a day of fasting and prayer observed the day before All Saint's Day which was itself a feast day. The day after All Saint's Day is called All Soul's Day and is itself a separate religious holiday.