They were not biding their time until the Sabbath was over in order to proceed with the Great. Divine. Plan because...they had no idea what the Great. Divine. Plan. was. They had no expectation of an empty tomb. Perhaps they spent this day (im)patiently waiting for observance of the Sabbath to pass. [Not that Jesus was all that strict a Sabbath rule follower and that scene in the temple seemed to imply that there was a whole new set of rules to be applied. Yet, women have learned since the dawn of time that standing in front of a male dominated power structure and breaking the rules has some serious, often life threatening consequences.] More importantly I think, the women were no different from the others - when they watched Jesus die on that cross they were certain the story was over. They waited, ready to do the work of anointing Jesus' dead body on the morrow. Nothing more, nothing less. Deep grief.
In fact,they may have been watching for approaching danger, either Roman or Jew, come to arrest them because of their association with this Jesus. In the gospel of John the disciples (and I am sure it wasn't just men) had locked themselves in an upper room because of their fear. They may have been keeping an eye on each other - wondering if there was another Judas among them.
We, on the other hand, are not observing some religious rule in our waiting for this holy day to pass. Neither are we watching for the danger of approaching authorities, nor the betrayal of a Judas. We are not making plans for purchasing spices to anoint a dead body. We do not hang in suspense whether the tomb will truly be empty on the morrow. The Easter proclamation "He is not here. He has been raised." was the dawn of a new creation. The Jesus who was raised then, is raised now. The tomb is forever and eternally empty.
However, this might be true. On that day of waiting and watching, the disciples were weighed down with love and grief. On this day of waiting and watching, we are weighed down with disbelief - or perhaps even worse, disinterest. The disciples were so close they could barely breathe; we are so far distant we barely pay attention. Our danger is not in the authorities but in our disconnect from the Divine Story, and the wondrous grace being poured out. We wonder what difference this makes, even if it is true.
I too have been paralyzed by the disbelief of sudden grief and loss. It is difficult, painful, lasting. In the end, it is preferrable to the empty void of meaninglessness carved out by a life of unbelief.
We wait with longing for the sunrise on the morrow and the proclamation, once again, He is Risen! He is risen indeed! because, in the end, our very lives are found in those words and in that Savior.