One of the two ecumenical memorial Saturdays falls on the eve of the Holy Trinity - June 11, 2022. Hence the name - Trinity parental Saturday.Orthodox pray for the repose of all the dead who have lived on earth, starting from the "time of Adam", for the forgiveness of their sins.
Such a special commemoration of the dead was established on the eve of the day of the Holy Trinity for a specific reason. Believers remember the descent of the Holy Spirit on the apostles, they talk about his life-giving power, that he has no boundaries, acts on the living and the dead.
Divine Liturgy is held in churches. The deceased can no longer repent themselves, so the living ask God for mercy on them.
After the service, the commemoration of relatives and friends in the cemetery is welcomed. On this day, it is customary to cover the graves with flowers and herbs. Our ancestors believed that the soul on the eve of the Trinity returns to this world, and it must be met with special honors.
Source: https://iz.ru/1345473/2022-06-10/troitckaia-vselenskaia-parentelskaia-subbota-2022-kak-pominat-chto-nelzia-delat