石の上にも三年
Perseverance will not fail of its reward.
over the past three years
the ensuing three years
まる3年
for three consecutive years
I lie fallow for three years.
a three-year period
occurring every third year or lasting 3 years
something that was born three years ago
It is a question of three years' standing.
Three years have passed―Three years have elapsed―since then.
It had happened three years before―three years since―three years back.