The BOJ seems to like this word and it is translated as either "epoch-making" or "groundbreaking"
この点、日本銀行は、1月の金融政策決定会合において、自らの判断で「物価安定の目標」を消費者物価の前年比上昇率2%と定め、これをできるだけ早期に実現するという画期的な約束をしました。
At the Monetary Policy Meeting held in January, the Bank -- on its own judgment -- set the price stability target at 2 percent in terms of the year-on-year rate of change in the consumer price index (CPI) and made a groundbreaking commitment to achieve that target at the earliest possible time.
In other places the BOJ has translated this as "epoch-making." But epoch-making events to a native English speaker would mean like ... the fall of Rome rather than a small change in the policy of a central bank.
I get the basic etymology of what's going on with the Japanese but I have a two-part question arising from this:
(1) Does this word's meaning really rise to the level of creating a new epoch in Japan? (2) What more natural equivalent can you think of for the English?
Examples always help!