wee hours

Noun

plural plural-only

The very early morning; the early morning hours; the nighttime hours following midnight, when most people are asleep.

Japanese Meaning

未明（深夜から早朝にかけて、ほとんどの人が眠っている時間帯） / 夜明け前（本格的な朝の光が差し始める前の非常に早い時間帯）

She finished writing the report in the wee hours.

彼女は未明にレポートを書き終えた。

Sense（1）

The very early morning; the early morning hours; the nighttime hours following midnight, when most people are asleep.