Souls in Purgatory

How can time apply to the souls in purgatory, as we pray for them long after they are dead EHC THE PROBLEM for us on earth when we ponder over eternity is that we think in space and time since that is the condition in which we live.
This can introduce • problems for us, even with God's own revelation. For example, when St John says "God loved the world so much that He sent his only begotten Son" we are referring a concrete historical event to the eternal, unchanging God.
And although we wriggle a bit with the unchanging mind of God choosing to do this from all
eternity, we humans, nevertheless, have problems both in understanding and expression.
The notion of purgatory is also plagued by its place in the history of indulgences, where under the pre-Paul Vi situation, the days and years attached to certain prayers referred to the worth of earthly time in relation to the soul's progress through
purgatory rather than to their stay there.
Indulgences are now much neater, with just partial and plenary, but the problem of time and purgatory itself is still there.
How souls, in their immortal state, pass (presumably in time) from a purgative state to a Heavenly state is not known. It is possible that since the immortal state for souls has to have some relation to time for it to begin (the point of human death), so also although purgatory is a purely spiritual state, nevertheless, there is an element of time in it, and true, unchanging eternity will only laegin in Heaven.
Another approach to purgatory consists in God foreseeing our prayers for the Holy Souls before they are made, and acting on them in advance and thus eliminating temporal progression through purgatory. But I have never really understood that way of looking at it.
Queries, please, to Fr P Sanders, Question Box, Catholic Herald, Herald House, Lambs Passage, I Bunhill Row, LondorrEC1.