I've often wondered how long Adam was in the garden before he fell. I think it could have been millillions years. I surely dont believe that God created him at 8 in the morning and by lunch time he fell. But thats the perception that is given when we talk of the fall.
We can only guess. But I think itnwouldn't take too long for their restraint to fail.
God created a beautiful Paradise for them to explore. He ordered Adam to name all the animals and botanicals. Adam had a photographic memory no doubt. So let's say there were 20,000 original kinds of animals and about 1000 botanicals (that eventually all generated into what we see today). Each day Adam & Eve went out to explore this massive Garden to accomplish this task. It would take some time. Avoiding one tree wasn't difficult when they had so much to interest them and consume their days, weeks and months - not to mention sex. No let's do mention that. It didn't take too long for them to figure out that activity and not too long for her to get pregnant. I would say that they got kicked out before she gave birth and that birth came with pain.
But back to their job. Let's imagine that this Garden was likely hundreds of square miles or more. If Adam could name 100 animals and botanicals per day while roaming through let's say five square miles a day, it would take 7 months before you finished the task. Animals themselves are fascinating. We relate to them and spend much time getting to know them. I submit that they knew the entire Garden and all that was in it before it was taken away.
From the beginning of their exploratory journey, they passed the forbidden fruit by many times and just discarded the thought, a mild temptation that they dismissed. But after completing tha task at hand, the temptation began to weigh heavier on them. They had enjoyed all there was to enjoy; and btw, God wanted them to experience all the the Garden offered before he knew they would fall. He wanted them to know completely the life they ruined and were being going to be deprived of.
It is likely God did not allow Satan to do his thing until enough time passed. Satan does wait for the right time to tempt us, when we are most vulnerable ... or filled up with everything else -- except that one thing missing.
So, there it is, my conjecture at best says they were there for less than nine months.