When the Dharma will have been forgotten by most

No, it isn't. The next Buddha is going to arise after that uncountable years.

In commentary wrote about the Anāgāmi-Brahmma (non-returning) told MahāpurissaLakkhana 32 (32 Marks of the Great Noble Person) to the ancient anchoret in Ariyan's country, then the Ariyan-anchoret it from generation to generation with some distorted.

In my opinion, the Anāgāmi-Brahmma told the Bigbang theory to them too, so we can see the Bigbang theory in Tipitaka and commentaries.

According to that Bigbang theory in Tipitaka and commenrary, each universe's cycle has 4 parts, falling down, it's stable, growing up, it's stable. The last is when we are. This part has many sub cycles too, the average is every 100 years human being's age increased in the moralist cycle's part, and decreased in the opposite part. It's uncountable years which increasing/decreasing (in average) from 10 human years old average to uncountable human years old average and this sub-cycles loop many times too.

We are in the immoralist part and the buddha can arise only in this part of sub cycles, so the next Buddha, Metteyya-SamBuddha, is going to arise in the next immoralist sub cycles, which is uncountable years. And the next from Metteyya is very very far more than this period because after Metteyya will have arosen, it is going to be the main Bigbang 3 cycle's parts which is very long long long long time.

We should enlighten as correct and as fast as we can because there's no any confirmation when our next Buddha meeting will be because we missing mostly.

See DN 26 Sutta. Tī. Pā. Cakkavattisuttaṃ and it's commentary with Dī.A. (sumaṅgala) Lakkhaṇasutta's commentary.

The exact duration is irrelevant.

What is more important is the criteria to determine HOW the Dhamma will be forgotten, and not WHEN.

The highlighted paragraph below shows HOW it will be forgotten - when monks (and I guess also lay Buddhists) do not want to listen to the teachings of the Buddha or pay attention or apply their minds to it. Instead, they will listen to the teachings of unenlightened teachers/ poets which are phrased in fancy ways.

Even today, we can find a number of new age gurus in the last 50 years, who have a lot of followers, writing bestselling books or giving speeches using fancy jargon or technobabble such as "quantum healing" or "inner engineering", and appearing on TV shows or YouTube.

From the Drum Peg Sutta (SN 20.7):

“Once upon a time, mendicants, the Dasārahas had a clay drum called the Commander. Each time the Commander split they repaired it by inserting another peg. But there came a time when the clay drum Commander’s original wooden rim disappeared and only a mass of pegs remained.

In the same way, in a future time there will be mendicants who won’t want to listen when discourses spoken by the Realized One—deep, profound, transcendent, dealing with emptiness—are being recited. They won’t pay attention or apply their minds to understand them, nor will they think those teachings are worth learning and memorizing.

But when discourses composed by poets—poetry, with fancy words and phrases, composed by outsiders or spoken by disciples—are being recited they will want to listen. They’ll pay attention and apply their minds to understand them, and they’ll think those teachings are worth learning and memorizing. And that is how the discourses spoken by the Realized One—deep, profound, transcendent, dealing with emptiness—will disappear.

So you should train like this: ‘When discourses spoken by the Realized One—deep, profound, transcendent, dealing with emptiness—are being recited we will want to listen. We will pay attention and apply our minds to understand them, and we will think those teachings are worth learning and memorizing.’ That’s how you should train.”

It's said, good householder, interested, by the Sublime Buddha that when the Vinaya get's lost, e.g. would no more be followed, the Dhamma get's lost. Since the Sangha of Bhikkhus is carrier of both, all resists and falls with it, in our current time even on further existance. Once the path is no more in it's whole practiced, Vinaya decays and Monks get more and more householders and lay servants, the Dhamma in it's meaning and understanding get's lost as well.

This generation actually on the peak toward the cliff of total disappearing will be the last where "real" Sangha, Monks could be found since it is no to expected that strong changes in tendecies will arise and those who practice straight forward as real homeless are already very hard to find.

In regard of "for the most", this point of time has already been reached about the same time the last Sangha - Gathering was held in the 50th of last century.

Althought the are numbers abd amounts found in the scripts, the fundamental way of Dhamma and the natural law is always one of cause and effect: "from this, that come, from arising of that, this arises. As soon as the tendency of the monks is toward settle near and with laypeople, do not follow the most simple ways anymore, (especially in regard of remote dwelling but also in regard of food, robes and medicine, that's the point Vinaya strated to get lost, no more followed in it's details, and with it a lay-practice, a secular way starts to develop. As sample one could investigate Sanghas history of decay in the north, China and specially merely isolated Japan.

So here you are, and now, what does good householder think would be most wise for himself to go after?

[Note that this isn't given for exchange, stacjs, what ever trades toward decay but for an escape from this bounds]

Dharma has been forgotten when the majority of one's actions are made with the agenda of taking advantage of another rather than giving advantage to another.

'Throwing pearls before pigs' is not an act compassion, letting the pig free to be a pig is. Contemplating one's own image while ignoring the sufferings of the Lady's path is ignoring the suffering of Compassion herself. Is that not the path of Ignorance and forgetting the whole premise of cultivating?

The semantics of what is good, what is bad, who is right and who is wrong all come with agendas. Is there harmony to the conflict? At what point shall the war start?

Take time throughout your day to 'measure' the heart of your simple actions of enacting whimsical compassion for the sake of offering with no expectation for reward. Those who struggle to muster one day feeling weightless in this dense, muddy world run by the currency of suffering, you are misled. One day of training is not enough for marathon.

Your path should be effortless.

So to answer your question Danyaal, when enough is sacrificed for the accruement of suffering. When 'life' has a price and the world has become merely a resource.

This is subtle, and difficult. As I see it, the suggestion that the dharma has been 'forgotten by most' doesn't mean that the dharma has been 'literally' forgotten. It means that the proper sense of the dharma has been lost; that people still (in good faith) teach and learn what they call the dharma, but that the 'dharma' they teach and learn is the wrong path, leading astray and accomplishing little.

This is something that happens to every faith, given enough time. It's an aspect the 'perennial philosophy', in which a single, common, deep understanding of the world consistently blooms, decays, and blooms again, each time different and each time the same. This perennial philosophy flowers as inspiration, then it bears fruit as goodness and rightness, then the fruit falls to the ground as rigid moral precepts, which then decay and die. But out of that decay a new flower blossoms.

Do we really learn these days what the Buddha taught? Do we really 'know' what that might be? The nature of being tathagata is to set an example that others can follow — to be the one who has 'gone' so that others can see the path ahead — but how long after the passing of a there-goer can we still 'see' him? And when his example has lost all force, what can we do except blindly follow what we think we know, until a new tathagata arises and corrects our course?

Meh, I'm waxing metaphysical, and that's never a good sign. Enough said...

The definition of "most" is indeed rather ambiguous. But if you think about it, the very notion of "Dharma have been forgotten" is also rather ambiguous, too: should we consider it forgotten when there's no-one left who can clearly explain phases of gradual arising of self-centred consciousness? Or is it when most Buddhists don't understand the unifying theme behind the steps of the Noble Eightfold Path? Or is it when only a few understand the nature of Dukkha and the exact conditions when it arises? Or is it when no-one seem to remember what Liberation and Nirvana actually refer to and what the word 'suchness' supposed to mean? Or when even the most of the so-called monks can't clearly explain the progression of Jhanas and how it fits with the rest of the teaching?

It seems to me, based on these basic criteria, I can hardly say that Dharma hasn't been forgotten already. I wish I was wrong but it will take some serious effort to convince me.