How long did the Cherubs guard the entrance to Eden?

Perhaps until the time of the Flood, over 1,600 years later!

There is reason to believe that the Cherubs were still guarding the entrance to Eden when Cain and Abel were growing up. It always takes time for things to over grow so no man would be able to say how many years it may have taken before the garden was no more, at least not like it was when Adam lived in it. We know that the Cherubs were faithful until God told them they no longer had to guard it. Why not look into the lives of faithful humans like Noah, Abraham, Moses, Sarah, Esther and Jesus to name just a few. The Bible is the best source of finding out about faithful ones who were blessed by God during their lives. There is an international website that millions earth-wide are looking into for truthful answers to their Bible questions such as yours. Find truthful answers at jw.org and Bible Teachings > Bible Questions Answered. See how Jesus' followers are living their lives in obedience to God as they "preach the good news of the Kingdom of God" to their neighbors from door to door, on the street and anywhere people are to be found. Matthew 24:14 Luke 10:1-12 Yes, people earth-wide are studying the Bible and appreciating what God is telling all of us about a marvelous future that is in store for those who exercise faith in the ransom sacrifice of Jesus Christ. John 3:16 and 17 John 17:3 and many other Scriptures. Find the answers you are looking for on the jw.org website of over 700 languages. Bible studies are free and personal and are at your convenience.

the Bible does not state how long the cherubs remained to guard the way of the tree of life, it may have been that such an arrangement existed until the Flood, 1,656 years after the creation of Adam.

Untended by Adam, who with Eve had been driven out for their disobedience in eating from the forbidden tree of the knowledge of good and bad, the garden likely suffered deterioration.

At any rate, it would at the latest have been obliterated by means of the Flood.

Till the Flood.

2 weeks

Scriptually, for eternity. Or at least until there is no man who could try and force their way back in.

It was a permanent expulsion until the eschaton.

John, makes some crap up later on claiming the tree of life had 12 different types of fruit - not mentioned in either genesis myth. So we can ignore him. As usual.

Bible does not say. My guess is long enough to keep people from returning.

5 hours, 2 minutes, and 3 seconds. After that, they went to the pub to get wasted and sexually harass waitresses.

Still guarding it and the tree of everlasting life. If we ever ate from it God would be in big big trouble, so they are still guarding it.

they are still on duty