last summer or in last summer

[Sweatpea]

I found a sentence in the beginning of a story saying, "From the moment they were announced last summer, ...". Can we say in last summer ? How different are they?

 

[emsr2d2]

I found a sentence in the beginning of a story saying, "From the moment they were announced last summer, ...". Can we say in last summer ? How different are they?

We don't use a preposition before "last" here.

In the summer, ...
In summer, ...
Last summer, ...
Next summer, ...

The exam results were announced last week.
When the results were announced last week, many children were ecstatic to find they had passed all their exams.