on in years

be a hundred years too early

To be so immature and unprepared as to have no hope of achieving an accomplishment.

donkey's years

A long time, years and years.

four score and seven years ago

Used (sometimes sarcastically) to indicate that a past event being mentioned is particularly important: a long time ago; many years ago.

golden years

Old age; especially, the leisure years in later life after one has retired from employment.

never in a million years

Absolutely not.

not in a million years

Alternative form of never in a million years.

roll back the years

To produce a sense of nostalgia.

term of years

The lease under which that estate in land is held.