前夕 (qián xī) — the eve of (a specific day); (figurative) the period just before an important event

Definition

Examples

• 中秋节前夕，一家人开始准备月饼和水果。
  Zhōng qiū jié qián xī, yì jiā rén kāi shǐ zhǔn bèi yuè bing hé shuǐ guǒ.
  On the eve of Mid-Autumn Festival, the family starts preparing mooncakes and fruit.
• 比赛前夕，他紧张得睡不着觉。
  Bǐ sài qián xī, tā jǐn zhāng dé shuì bù zháo jué.
  On the eve of the competition, he was so nervous he couldn't fall asleep.
• 毕业前夕，我们常常聊到深夜。
  Bì yè qián xī, wǒ men cháng cháng liáo dào shēn yè.
  On the eve of graduation, we often talked until late at night.

Origin