The scripture doesn't tell us much about Saturday, we know that Jesus' followers were mostly hiding. But was Jesus doing anything on Saturday? Yes He was! Jesus descended into the depths of hell and conquered the devil and death. The battle on the cross was against the sins of man, but in that battle the souls of those who believed in the promise of messiah, having not seen Him but having faith in Him, were also redeemed. Jesus now goes to reclaim those who He has redeemed.
He leads them up to The Father and takes the keys of hell and death with him. He has conquered mans greatest enemy and for eternity removed the curse of death to those who believe, hallelujah!