Is it until Judgement Day?
According to Judaism, no more than 11 months, except for the truly incorrigibles, who need the full year. There is no atonement process on the Sabbath, however. In Catholicism, I’m not sure there’s a specific time limit; it all depends on how much cleansing one needs.
We can’t really know. It probably happens outside of time anyway. It’s a mystery. Some things are for God alone to know.
This…
The question of “how long” becomes incomprehensible the moment we begin to discuss anything not dogmatically revealed outside of the physical experience within THIS universe (which is the only place we empirically KNOW that time as a dimension exists)
Only God knows.
Purgatory will only exist until the final judgement. After a soul is judged during the final judgement, all just souls will go to Heaven, while all others will be sent to hell. Purgatory will no longer exist after the final judgement.
Scripture says that nothing unclean can enter heaven.
“There shall not enter into it any thing defiled, or that worketh abomination or maketh a lie, but they that are written in the book of life of the Lamb.” (Revelation 21:27)
Now how long will a soul stay in Purgatory? Well, if a soul is in Purgatory, it is eventually going to make it to Heaven. The length of a souls stay in Purgatory depends on how much “cleansing” it needs. To enter Heaven, we must be clean, and Purgatory is what purifies the soul and prepares it to enter Heaven. Again, it depends on how much “purification” one needs.
Some will be there until the end.
But really, the answer is, “until they’re purified.” I heard a talk on EWTN years ago and a woman said the root word in Purgatory is the same word for refining metal, sorta like smelting. It’s a process of driving out impurities. She said a silversmith was once showing her the process and she asked him how he knew he was done. His answer: when you can see a reflection. This speaker (can’t remember who!) said she thinks of Purgatory as driving out our impurities until we’re a reflection of Christ. Works for me.
Anyway, you can hasten the release of the Souls in Purgatory by praying for them. Maybe one of your prayers would be the magic one that gets a Soul released…how’d you like to have a Saint on your debt? 
Remember that praying for and having Masses said for the dead helps much! They cannot pray for themselves while they are there, and depend on us.
It seems that time runs differently in Purgatory. Even if someone passed on a few weeks ago, it feels like years. Check out Hungry Souls by Gerard van den Aardweg.
There is no time in Purgatory, however, I understand what you are asking.
A soul stays in purgatory for as long as need be. Until he is cleansed.
Not to be provocative, but can you clarify the contradiction you’ve stated? You said there’s no time then stated “as long” and “until”, words that denote a measure of change/time.
Can anyone present de Fide material that states purgatory is outside of time?
Purgatory is not a physical place, so it does not have time as we conceive it currently within THIS temporal universe.
HOWEVER, purgatory is a process, and it only exists until the final judgement, so we can conclude that there is SOME sort of “time” there, in that there is progression of being, but this time is non-sensical to us because we lack any sort of faculty to observe it.
In other words, it is not contradictory to state that there is no time in purgatory (at least, not as we understand time), and yet to state that a soul spends a certain duration in purgation until it is pure and enters heaven.
For all we know, it is timeless in the sense that God is timeless and yet still has progression relative to Earth’s understanding…
How long?? It’s a question that Catholics cannot answer. Purgatory is not based in biblical explicit terms but yet its in tradition. Those two ingredients make purgatory puzzling for many Catholics.
As others have said, we can’t really say how long a soul will stay in Purgatory however we can say that a soul will be in a state of purgation for as long as it needs to be in order to be cleansed to the point of perfection so it can enter Heaven. That said, I would be willing to stay in Purgatory for a very very long time if it meant that I would go to Heaven. I would rather be in Purgatory for 5,000 years than in Hell for 1 minute. And yes, I know that the eternal realm is outside of what we know as time but I am using measures of time to make a point.
I like the way you think. 
I was about to ask, “If Purgatory dissolves at the Last Judgment, how is it just to those who died right before and had a lot of time they needed to spend in cleansing?” But when you explain time in that manner, in a sense saying “It doesn’t make sense,” then I guess it makes more sense. :whacky:
Consequently, having the mindset that souls spend a definite amount of Earth-time in Purgatory, and then believing that everyone in Purgatory goes to Heaven at the Last Judgment, seems a bit contradictory–at least, considering the Church’s teaching that every soul needs to go through a certain amount of cleansing for their sin.
Thanks! Though I can’t take the credit, I derived the thoughts on it from another lesson in my Philosophy of Religion class…
…namely that God exists outside of time, and “created” (a process which implies time) Angels who exist outside of time, and then afterwards “created” (another process which implies time)… and then we go on to say that God preexisted angels… a concept which is non-sensical if we imagine NO time whatsoever, at least from our perspective.
So we only lightly touched on the subject, but the long and short of it was that God is not OUTSIDE of all time, but rather that God is in “God Time”, a sense of time that is significantly different from ours, and, as I understood the vastly complex idea that the professor was getting at (this was post-grad material being taught at the end of the semester after we finished the syllabus for the undergrad class), this time is presumed to be hierarchal in nature rather than temporal… something about God’s preexistence is such because He is more preemenantly existant… all of it is lost on me though, so I just simplify it by saying that we can assume there is SOME sort of time, but that this time is necessarily incomprehensible to us.:shrug:
Here are my speculative thoughts.
Purgatory is not in time.
Purgatory is more a state than a place.
Purgatory is complete when the soul is fully sanctified, i.e. cleansed of all unrighteousness.
The scriptures say "we will be changed in the twinkling of an eye.
The scriptures say that “he will be saved but as if through fire”
With these facts in mind I tend to think that Purgatory, timewise may not be of any duration but perhaps is more an intensity based on the amount of purification we need. When we die we will be judged and in that judgement we will see Christ and know how greatly he is to be loved and how little we have loved him by our lives. We will love him and be to some degree apart from him. The intensity of the purgatorial experience therefore may be like the pain one experiences in life being away from a loved one. It may be that a few minutes might seem like hours or years.
The philosophical word you’re looking for to explain the continuum between eternity and time is aeviternity. I’ve been contemplating for a couple of days whether this applies to purgatory, though the main concern is those in aeviternal existence, angels and the elect, do not experience change in the degree of their being, for they reached the perfection of being by participation of the perfect being. Those in purgatory experience changableness in the degree of their being.
No, the angels and elect certainly don’t realize a change in the degre of their being… and yet we can pray to them, ask for their intercession, which they will then pray for (if it is the will of God)… this stimulus response likewise implies some sort of time, an aeviternity as you put it.
Of course it could be that THIS time, the time of the saints, angels, and God, is entirely different from whatever sort of time there might be RE: purgation, but :shrug: we will never know in this life unless God chooses to reveal it…
Souls stay in Purgatory until they are cleansed. Only God knows how long that will be and what that purification would entail exactly, but I would suspect that different souls would need a different amount of purification and so would stay in Purgatory for different amounts of time.