What is the difference between these two sentences:
It is September.
It is in September.
There seems a difference, but I don't know it.
When to use the one over the other?
What is the difference between these two sentences:
It is September.
It is in September.
There seems a difference, but I don't know it.
When to use the one over the other?
Generally speaking, the following is how you would interpret the two sentences.
It is September.
This means that the current month is September.
It is in September.
Purely on its own, this sentence is awkward and unidiomatic. If we mean to say that the current month is September, we never say it is in September.
However, the sentence makes sense if the pronoun is referring to some kind of event:
"When is the wedding?"
"It is (scheduled to be) in September."
Note that there are some alternatives to a standalone sentence about it being September—one even uses in and doesn't refer to an event:
It is now September.
We find ourselves in September.