summer days前用什么介词

summer days前用介词on，on summer days中文意思是“在夏日”

We're going away on summer days 夏天我们要外出。

It's very hot here on summer days 这里夏天很热。

The whole summer lay before me.整个夏季正等待着我。

I saw him sometime last summer.我去年夏天什么时候见过他。