"As the name implies, they're rings that allow you to move freely through time...But only to the future. We can only go to the future, and then back to the timeline from which we came."
The Time Rings (時の指輪 Toki no Yubiwa) are accessories of the Supreme Kai which enable them to travel through time. They are normally used to observe future events in their main timeline.
The Time Rings have several special abilities, unlike the Time Machines created by Capsule Corporation, the Time Ring allows for "natural" time travel, and so does not create alternate timelines when used. Additionally, a wearer of a Time Ring will be granted acausality, and so even if their past were to be altered somehow - they would not be affected, as shown with the case of the original present Zamasu, as while the Zamasu from the altered main timeline was killed by Beerus due to Future Trunks altering the timeline, the original present Zamasu still continued to exist with his unaltered history thanks to his Time Ring.
It had been said that the Time Rings were used and only worn by the Supreme Kais who often used them to travel through time. Sharing a Potara earring with a full ranked Supreme Kai is required in order for anyone to use the Time Ring, as explained by Gowasu. Despite this, they're only used in very rare occasions, and the last time it was used in Universe 10 was 400 years before Gowasu became a Supreme Kai apprentice.
Green time rings represent the creation of alternate timelines. Thus, the number of green rings indicate how many people have travelled into the past. A new ring is created whenever another person modifies the past. There are 4 green time rings and a silver one implying there are 5 timelines, however, it could be that the silver time ring is the one for the timeline it came from, while the green rings are possible timelines one can travel to. So the silver ring can travel to the timelines of any of the 4 rings (Timeline 1, 2, 3, and 4). Meaning there are actually only 4 timelines. If a silver ring is destroyed, the corresponding green ones will be too, making travelling to the corresponding timeline via time rings no longer possible, but other time-travelling methods still work. For example, after Future Zeno had erased everything within his timeline (including its time ring box containing its silver ring), Goku and Future Trunks were still able to return to pick him up.
The Time Ring is sensitive to disturbances in time that has been recently altered by an individual. Once the Time Ring is activated, a warp is created in the form of a dark portal, allowing the user to travel between past, present and/or future altered destinations for a short period of time, before the distortion in time and space returns to normal, pulling the user back to its original plane, sealing off that era of time.
Goku Black used the power of the Time Ring to find Future Trunks in the present timeline after he escaped using his Time Machine, but could only stay for a small amount of time before being forced back. Black only managed to go back in time because the Time Machine's journey into the past created a distortion in time and space, which the Time Ring reacted to and opened a portal into the past era.
According to Whis, the Time Rings are only used to travel to the future and then return to the present. Using the ring to travel to the past should be theoretically impossible and the user cannot travel back through time on their own free will. Also, only the Supreme Kais are allowed to wear them.
According to Beerus, if a god alters history, it would affect the future of a different timeline. Goku Black is the Zamasu of the same timeline in which he was killed by Beerus in the present, but because he was wearing the Time Ring, he was unaffected by changes in the past. Future Zamasu was the Zamasu of Future Trunks' timeline, so he was not affected by present-day Zamasu's death, with a new time ring being created as a result.
In the manga, the erasure of a timeline's multiverse has also been shown to lead to that multiverse's time ring being destroyed, as is the case with Future Trunks' original timeline. Possibly due to Universe 10's erasure, the Time Rings being stored away in Universe 10 would be gone as well.
Time Travel Procedure
As demonstrated by Gowasu and Zamasu, in order for one to time travel using a Time Ring, the one not wearing the ring must touch it with their fist, then both must say the number of years they wish to travel.
Alternatively, as demonstrated by Goku Black, when using a nearby distortion in time to time travel, the ring shimmers briefly before producing a thin beam of light that cleaves a portal in time (as though literally cutting through the space-time continuum) that can be used for travel (even to the past) until the distortion is corrected, at which point the wearer is forcibly returned to the era they just vacated.
Video Game Appearances
During the Warrior of Hope Saga from the Super Pack 4 DLC, the Time Rings are shown to react to the presence of Time Patrollers who have travelled through time using a Time Scroll alerting Goku Black and Future Zamasu to the two Future Warriors' identities as time travellers and it is implied that they are aware of their connection to the Supreme Kai of Time (as in the Extra Pack 1 DLC Future Zamasu is revealed to have heard of Chronoa and knows of her position as Supreme Kai of Time). Old Kai and Chronoa warn the Future Warriors to be careful as the Time Rings can allow Black and Future Zamasu to follow them through time thus they must be careful when returning to Age 852 to prevent Black and/or Future Zamasu from following them back to the Time Nest as the two would likely seek to gain control of the Time Vault to use as part of their Zero Mortals Plan if given the opportunity. This implies that the Time Rings are normally unable to travel to the Time Nest unless circumvented by following a Time Patroller back to it. Presumably, this may be a safeguard to prevent the Time Rings from being misused or Chronoa uses her power to prevent the Time Rings from accessing the Time Nest which is likely especially in light of Black and Future Zamasu's misuse of Time Rings as part of their Zero Mortals Plan. Additionally like in the anime, Goku Black travels to the main timeline using the time distortion created by Future Trunks' Time Machine. Thanks to the efforts of the 2nd Future Warrior, they hold off Black long enough for the time distortion to correct itself causing him to be sucked back into the future timeline, though he resists long enough to destroy the Time Machine, though this restores the correct timeline.
It is implied by Chronoa and Old Kai that the historical changes in Age 796 of the future timeline and Age 779 of the main timeline are the result of Goku Black and Future Zamasu's misuse of the Time Rings to ensure the success of their Project Zero Mortals. Old Kai considers the Time Rings extremely dangerous and even believes little good can come from their use implying he believes it is too dangerous for even gods to possess them as it can lead to them being abused as Goku Black and Future Zamasu demonstrated. During Supervillain Super Saiyan Rosé Goku Black's battle with Goku and Vegeta (during their third trip to the future timeline) he uses his Time Ring in conjunction with his scythe to create a massive rip in the fabric of time-space which Old Kai identifies as a Rift in Time. He states that creating holes in time like that is reckless, though it also explains how Supervillain Turles appears in Age 796. To make matters worse, during the battle with Turles, Goku carelessly drops Zeno's Button to the utter terror of Old Kai who knows that it is required to summon Future Zeno. Additionally, more villains show up forcing Goku, Vegeta, and the Future Warrior to defeat them to chase after Goku Black who had decided to fuse with his counterpart. Unfortunately for their fusion, the rift remained and ironically aided Future Trunks by allowing people from other timelines (such as Present Gohan, Present Piccolo, Future Gohan, Teen Future Trunks, GT Trunks, GT Goku, GT Pan, and Trunks: Xeno) to lend their energy to Future Trunks, allowing him to channel it into his Light Sword to create the Sword of Hope and physically kill Grotesque Zamasu with his Final Hope Slash, which caused the rift to close. Old Kai notes while the rift brought evil it also brought good power that was desperately needed and Chronoa surmises everyone helped Future Trunks because they sensed his desire to protect the integrity of the future. Additionally, Zeno's Button was later returned to Goku by the legendary Toki Toki City Hero foiling Infinite Zamasu's attack on the Time Nest as he was erased by Future Zeno in Age 796 like in the original timeline. Interestingly Grotesque Zamasu's Time Ring increases in size with his enlarged hand and it is implied that its destruction along with Grotesque Zamasu's physical body was what caused the Rift in Time Black created to close.
Old Kai also notes that whatever the timeline, Time Rings usually bring nothing but trouble indicating they may have been abused in other timelines, though he may just be exaggerating as he likely sees them in the same vein as Dragon Balls and Time Machines as they all violate the natural order of the universe in his eyes (though he is more forgiving when it comes to Time Scrolls and methods of time travel used by the Time Patrol as they are meant to ensure the natural order and official history are maintained, though he still complains about the use of Time Machines and Dragon Balls even if it part of the official history though this is mostly out of principle, while likely sees Time Rings as an item too dangerous for even the Supreme Kai to possess as while they cannot normally travel to the past, their reckless misuse can still be dangerous even to the user as shown by Grotesque Zamasu in Xenoverse 2).
It is implied that Time Rings can be used to follow Time Patrollers anywhere in spacetime presumably through the same path created by the Time Scroll (this path is temporally safe and does not distort time-space as it does not create alternate timelines) presumably due to the Time Rings reacting to a Time Patrol's unique method of time travel. However, all Time Patroller has to do is weaken the Time Ring wielder enough that they can't follow them immediately (presumably the path created by the time scrolls are temporary to prevent time from being distorted) or when the wielder is too distracted. It is also revealed that while travelling to the past is normally impossible if misused a Time Ring can alter history and create rifts in time that can connect multiple timelines together though the wielder has no control over what comes through these rifts. These rifts allow people and energy to travel between the connected timelines making Time Rings extremely dangerous to the natural order as these rifts can potentially be used to travel through time to other timelines and possibly even circumvent the Time Ring's inability to travel directly into the past, were a rift connected to it. Additionally, with so many timelines connected, the official history of those timelines is in danger of being altered by simply being connected to one another. Fortunately, Future Trunks was able to use the energy from across time to kill Grotesque Zamasu which closed the rift removing the threat both it and Grotesque Zamasu posed to history.
- The ring possesses an infinity symbol almost identical to that of the Time Breakers' logo.
- Time Rings are one of two methods of Time Travel available to the Supreme Kai the other being the Time Scrolls used to record history (though Time Scroll can be used by almost anyone as long as they have access to the Time Vault which is normally reserved for Chronoa and select members of the Time Patrol, as they allow travel to any point in the official history of various timelines). It is implied that Supreme Kai like Old Kai can use them to travel through time if permitted by Chronoa herself.
- In Universe 12, Agu has access to the very first Time Machine created in his Universe however it is unknown if he is permitted to use it. In the future timeline, this time machine fell into the hands of Goku Black and Future Zamasu when they killed him.
- Additionally Old Kai utilizes a Time Patrol sanctioned Time Machine (which are Time Distortion free) to access a Time Fragment during the Parallel Quest Tutorial in Xenoverse 2.
- Time Rings are the second form of Time Travel to be used by a main villain in the anime and manga the first being Cell's stolen Time Machine.