那天 + Clause
那天 (nà tiān) means "that day," used to refer to a specific day previously mentioned or understood from context. It anchors a narrative to a particular point in time that both speaker and listener can identify.
那天下了很大的雨,我们只好取消了野餐。
Nà tiān xià le hěn dà de yǔ, wǒmen zhǐhǎo qǔxiāo le yěcān.
It rained heavily that day, so we had no choice but to cancel the picnic.
你还记得那天我们一起去爬山吗?
Nǐ hái jìde nà tiān wǒmen yīqǐ qù páshān ma?
Do you still remember the day we went hiking together?
那天她迟到了,因为路上堵车堵了一个小时。
Nà tiān tā chídào le, yīnwèi lùshang dǔchē dǔ le yī gè xiǎoshí.
She was late that day because she was stuck in traffic for an hour on the way.