How long was Sam wearing the Ring?

Question

At the end of The Lord Of The Rings: Two Towers, Sam puts the Ring on to hide from orcs and then follow them, and afterwards passes out.

Now the flicker of approaching torches and the clink of steel ahead was very near. In a minute they would reach the top and be on him. He had taken too long in making up his mind, and now it was no good. How could he escape, or save himself, or save the Ring? The Ring. He was not aware of any thought or decision. He simply found himself drawing out the chain and taking the Ring in his hand. The head of the orc-company appeared in the Cleft right before him. Then he put it on.

[...]

The great doors slammed to. Boom. The bars of iron fell into place inside. Clang. The gate was shut. Sam hurled himself against the bolted brazen plates and fell senseless to the ground. He was out in the darkness. Frodo was alive but taken by the Enemy.

_{The Lord Of The Rings: Two Towers, Book IV, Chapter 10, The Choices of Master Samwise}

I didn't find any mention of him taking the Ring off, but then, in The Return of the King

There he halted and sat down. For the moment he could drive himself no further. He felt that if once he went beyond the crown of the pass and took one step veritably down into the land of Mordor, that step would be irrevocable. He could never come back. Without any clear purpose he drew out the Ring and put it on again. Immediately he felt the great burden of its weight, and felt afresh, but now more strong and urgent than ever, the malice of the Eye of Mordor, searching, trying to pierce the shadows that it had made for its own defence, but which now hindered it in its unquiet and doubt.

_{The Lord Of The Rings: The Return of the King, Book VI, Chapter 1, The Tower of Cirith Ungol}

That supposes Sam was not wearing the Ring at the time.
So, when exactly did he take the Ring off? Was it before or after he was knocked unconscious?

Answer 1

He wore the Ring for about an hour

Although there is some discussion about this in the comments on the question, I believe the quote from the start of Book VI ("he drew out the Ring and put it on again") means that Sam was not wearing the Ring when he regained consciousness.

As he was certainly wearing the Ring when he lost consciousness at the end of Book IV, I believe that can only mean that the Ring slipped off his finger when he hit the door. The Ring would not have rolled away as it was on its chain that Sam wore round his neck. When he takes the ring and its chain from Frodo's seemingly dead body, we are told:

And then he bent his own neck and put the chain upon it, and at once his head was bowed to the ground with the weight of the Ring, as if a great stone had been strung on him.

_{The Lord of the Rings Book Four, Chapter 10: The Choices of Master Samwise
Page 733 (Houghton Mifflin Harcourt; Single Volume 50th Anniversary Edition)}

The text of The Choices of Master Samwise tells us that after Sam puts on the Ring, he:

• Waits for the two groups of orcs to approach.
• Listens to Gorbag and Shagrat greet each other.
• Sees the orcs discover Frodo's "body".
• Runs towards the orcs.
• Follows the orcs as they carry Frodo though the tunnel.
• Listens to Gorbag and Shagrat talk again. At this point, Shagrat says that is has been an hour since his group were sent out from the tower.
• Climbs over the stone blocking the passage and follows Gorbag and Shagrat to the door of the tower.

It seems to me that all those things should take no more than an hour. Shagrat's statement that his conversation with Gorbag was an hour after he was sent out from the tower also suggests that the time-frame is of the order of an hour.

I believe the answer to the posted question is that Sam wore the Ring for no more than an hour.

Spencer points out in a comment that Sam wears the Ring a second time (after all, he puts it on again in the second passage quoted in the question. However, he doesn't keep it on for long this time.

He puts on the Ring at the same place where he put it on the first time. After a pause for thought, he runs over the crown of the pass and down the hill towards the tower before taking off the Ring

He ran forward to the climbing path, and over it. At once the road turned left and plunged steeply down. Sam had crossed into Mordor.

He took off the Ring, moved it may be by some deep premonition of danger, though to himself he thought only that he wished to see more clearly.

_{The Lord of the Rings Book Six, Chapter 1: The Tower of Cirith Ungol
Page 899 (Houghton Mifflin Harcourt; Single Volume 50th Anniversary Edition)}

The place where Sam takes off the Ring is 200 feet above the main gate of the tower.

About the lowest tier, two hundred feet below where Sam now stood, there was a battlemented wall enclosing a narrow court.

_{The Lord of the Rings Book Six, Chapter 1: The Tower of Cirith Ungol
Page 900 (Houghton Mifflin Harcourt; Single Volume 50th Anniversary Edition)}

Based on Shagrat's estimate of an hour to make the round trip from the tower to where Frodo fell, the place where Sam put on the Ring couldn't be more than 30 minutes from the tower. From the description of Sam's movement with the Ring on and how much further he had to go to the tower entrance, it seems to me that he covered less than half the distance and he did it at a run. I estimate that thi second time he wore the Ring for perhaps 5-10 minutes.

Sam doesn't wear the ring in the tower. He is clutches it in his hand for a short time when he encounters an orc on the stairs.

His will was too weak and slow to restrain his hand. It dragged at the chain and clutched the Ring. But Sam did not put it on; for even as he clasped it to his breast, an orc came clattering down.

_{The Lord of the Rings Book Six, Chapter 1: The Tower of Cirith Ungol
Page 900 (Houghton Mifflin Harcourt; Single Volume 50th Anniversary Edition)}

Sam doesn't put on the Ring again before he gives it back to Frodo.

Based on all this, I estimate that the two times Sam wore the Ring add up to about one hour.