The feast of All Saints is a very joyful day. We remember all of the saints who are in Heaven. It is not just about those saints who have been formally canonised by the Church. While we can be sure that the canonised saints are indeed in Heaven, since the Church was moved and guided to proclaim certain exceptional people saints, we know that there must be others who are in Heaven even though their place has not been formally pronounced by the Church. So, even though one would not be advised to pray to uncanonised people as we cannot be sure whether or not they are in Heaven yet (eg. family and friends), it is nice to remember that some of the people we may have known may already be rejoicing with all the other saints in Heaven.
There is a change of mood and tone on the Commemoration of the Holy Souls. The focus is on those who are in Purgatory. That said, it is not all sadness for us who remember them, because we know that they are well on their way to Heaven. They are not yet saints in Heaven, but we know that one day they will join the great company of saints in Heaven. Our prayers for the Holy Souls - especially for family, friends and enemies - can hasten their onward journey to Heaven. Remember too, that the souls in Purgatory who benefit from our prayers are grateful for our intercessions, and one may be sure that when they are counted among the saints that we rejoice with on November 1, they will respond generously with intercessions for us.